OVERV[EW OF THE GEOLOGY AND VERTEBRATE BIOCHRONOLOGY OF THE LEISEY SHELL PIT LOCAL FAUNA, HILLSBOROUGH COUNTY, FLORIDA Gary S. Morgant and Richard C. Hulbert, Jr.2 ABSTRACT The Inisey Shell Pit Local Fauna was collected from two adjacent commercial shell mines located 7 km southwest of Ruskin and less than 1 km inland from Tampa Bay in Hillsborough County, Florida Leisey Shell Pit is one of the most diverse Irvingtonian vertebrate faunas in North America, composed of at least 203 species: 14 sharks, 9 rays, 50 bony fish, 3 amphibians, 26 reptiles. 52 birds, and 49 mammals. Leisey 1 A and Leisey 3A are the largest of the four principal sites that constitute the Lcisey Shell Pit Local Fauna. Leisey 1 A has extensive samples of large mammals, in particular: the camelids Palaeolama mirifica and Hemiauchenia macrocephala, two species of Equus, the primitive mammoth Mammuthus hayi, the ground sloths Paramylodon harlani and Nothrotheriops texanus, the *mt tapir Tapirus haysii, the peccary Platygonus vetus, the gracile sabercat Smilodon gracilis, the short-faced bear Arctodus pristinus, and the canid Canis edwardii. The large mammal fauna from Lcisey 3A is dominated by associated juvenile skeletons ofHemiauchenia macrocephala, while its diverse microvertebrate assemblage contains important samples offreshwater fish sirens, aquatic snakes, birds, and small mammals. Sediments in the Lcisey Shell Pit are referred to four formations, each of which has produced vertebrate fossils. At the base ofthe stratigraphic section is an indurated, tan to light gray dolostone referred to the Arcadia Formation. A horse tooth identified as "Merychippus" terfius derived from this unit is indicative of an early Barstovian age (early middle Miocene). Reworked sediments on top of the Arcadia Formation contain several land mammals, including the horses Nannippus aztecus, Neohippanon eurystyle, and Cormoh*parion ingenuum, whose association is characteristic of Florida late early Hemphillian (late Miocene) faunas. Phosphatic gravel and spheroidal metaquartzite pebbles in this unit are typical ofthe upper Bone Valley Formation. The major concentrations ofvertebrate fossils in the Leisey Shell Pit occur in thin. irregular layers of organic-rich sediment distributed throughout about 7 m of sandy marine shell beds referred to the Bermont Formation which unconfonnably overlies the Arcadia Formation. The large assemblage ofland mammals from these organic units in the Bennont Formation is early Irvingtonian (early Pleistocene) in age. Shell beds of the Fort Thompson Formation occur in the Leisey section above an 1 7De senior author is a paleontologist at the New Mexico Museum of Natural Histoly. 1801 Mountain Road NW. Albuquerque NM 87104- 1375 (formerly a Senior Biological Scientist at the Florida Museum of Natural History, P.O. Box I t 7800, Gainesville FL 32611.7800. USA). 2 The juniorauthoris an Assistant Professor ofGeology at Georgia Southern University, Statesboro GA 31460-8149, USA. MORGAN, G. S., and R. C. HULBERT, JR- 1995. Overview ofthe Geology and Vertebrate Biochronology of the L.eisey Shell Pit Local Fauna, Hillsborough County, Florida. Bull. Florida Mus. Nat Hist. 37 PL 1(1):1-92. 2 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 37, PT. I, NO. 1 erosional unconformity at the top of the Bermont Formation. The Fort Thompson shell beds contain a distinctly younger mammalian fauna, including the bison Bison sp., the cotton rat S,gmodon hispidus, and the tapir Tapirus veroensis, typical 6fthe late Pleistocene (Rancholabrean) Geochronological data derived from paleomagnetic analysis strontium isotope geochronology, sea levels, and molluscan and vertebrate biochronology have been incorporated in a multidisciplinary effort to determine the age of the Bermont Formation at the Leisey Shell Pit Molluscan biochronology implies an early or middle Pleistocene age, whereas mammalian biochronology is considerably more precise strongly favoring an early Pleistocene age between 1.6 and 1.0 Ma. All paleomagnetic samples from the Berm6nt Formation at Leiscy have reversed polarity and are referred to the Matuyama Chron, indicating an age greater than 0.78 Ma. The kisey Bermont section does not correlate to the Jaramillo Subchron of normal polarity between 1.07 and 0.99 Ma. It is also unlikely the Leisey beds were deposited during the youngest portion of the Matuyama between 0.99 and 0.78 Ma. The combination of data from magnetic polarity, mammalian biochronology, and sea level strongly indicates that the Bermont Formation at Ikisey is older than 1.07 Ma and younger than 1.55 Ma. Strontium isotope ratios from Chione cancellata (Mollusca) shells from Leisey indicate an age between 1 and 2 Ma. Leisey is younger than Florida's best known earliest Irvingtonian (latest Pliocene) faunas, Inglis 1 A and De Solo Shell Pit, based on the presence of five genera unknown in North America before the Pleistocene: Nothrotheriops, Lutra, Castoroides, Palaeolama, and Mammuthus. Four rodents from Uisey, Geomys pinetis, Erethizon dorsatum, Sigmodon libitinus, and Ondatra annectens. differ at the species level from their congeners at Inglis and De Soto. Leisey also lacks various Blancan holdover species found in the two older faunas, including the dwarf Florida form of Megatonyx leptostomus, Chasmaporthetes ossifragus, Trigonictis macrodon, and Capromeryx arizonensis. The occurrence of numerous species at Leisey that are unknown after the early Irvingtonian, including Glyptotherium arizonae, Pachyarmatherium leiseyi, Holmesina floridanus, Nothrotheriops texanus, Sigmodon libitinus, and Conis edwordii, further constrains the age ofthis fauna ruling out a middle Irvingtonian or younger age assignment The Leisey mammalian fauna correlates most closely with the late early Irvingtonian, between about 1.6 and 1.0 Ma Other Florida faunas similar in age to Leisey are Haile 164 Haile 214 Crystal River Power Plant, Pool Branch, Payne Creek Mine, Rigby Shell Pii and Punta Gorda. Ofthese sites Haile 16A is probably somewhat older (between 1.6 and 1.3 Ma) based on the occurrence of several holdovers from Florida late Blancan and earliest Irvingtonian faunas, including Sylvilagus webbi, Geomys propinetis. and Trigonictis. Western early Irvingtonian faunas that are correlatives of Leisey include: Gilliland, Texas; Holloman, Oklahoma. Kentuck, Nash, and Wathena in Kansas; Sappa, Nebraska; and Java, South Dakota Among these sites, Izisey has the largest number of diagnostic laxa in common with the Gilliland ucal ¥auna, mcluding Glyptotherium arizonae, a medium-sized Holmesina floridanus, Nothrotheriops texanus, Canis edwardii, Tapints haysi4 and primitive Mommuthus. Lcisey and other late early Irvingtonian faunas are younger than earliest Irvingtonian faunas (2.0 to 1.6 Ma) such as Curtis Ranch Arizona and Inglis l A and De Soto Shell Pit of Florida, and are older than middle Irvingtonian faunas ( 1.0-0.6 Ma), including: the type Irvington fauna from California; Cudahy, Kansas; Conard Fissure, Arkansas; Cumberland Cave, Masyland; Port Kennedy Cave, Pennsylvania; Hamilton Cave, West Virginia; and the Florida equivalent McLeod Limerock Mine. The occurrence of land mammals in estuarine, freshwater, and terrestrial units within the predominantly nearshore marine late Pliocene and Pleistocene shell bed sequence of southern peninsular Florida (Pinecrest Beds, Caloosahatchee Formation, Bermont Formation, and Fort Thompson Formation in ascending stratigraphic order) has allowed a precision in dating these deposits not previously possible. The Pinecrest Beds, the uppermost unit ofthe Tamiami,Formation, contain land mammal faunas of late Blancan age (2.5-2.0 Ma) based on the association of Nannippus and a large suite of Neotropical immigrants, includmg Dasypus, Holmesina, Glyptotherium. Glossotherium, Eremotherium, and Neochoents. Florida late Blancan faunas derived from the Pinecrest Beds, or found in association with Pinecrest molluscan faunas, include Macasphalt Shell Pit~ Acline Shell Pit, St Petersburg Times Kissimmee River, Brighton Canal, and Lehigh Acres. Vertebrate faunas from the overlying Caloosahatchee Formation lack typical Blancan forms, including Borophagus, Nannippus, Equus (Polichohippus), and Rhynchotherium, and contain taxa typical of earliest Irvingtonian (2.0-1.6 Ma) faunas, such as Inglis IA. The two richest earliest MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 3 Irvingtonian faunas from the Caloosahatchee Formation in southern Florida are the De Soto Shell Pit and Forsberg Shell Pit. Vertebrate faunas from the Bermont Formation are late early Irvingtonian (1.6-1.0 Ma) in age, and are typified by the Lcisey Shell Pit. as well as Rigby Shell Pit, Crystal River Power Plant, and Punta Gorda. Vertebrate faunas associated with the Fort Thompson Formation typically contain Bison and other tan characteristic of the Rancholabrean und Mammal Age. RESUMEN La Fauna Local del Depdsito de Conchuelas de Lcisey fue colectada de dos minas de conchuela comerciales adyacentesylocalizadas 7 km al suroeste de Ruskin y a menos de 1 km lima adentro dela Bahia de Tampa, en el Condado-Hillsborough, Florida. La fauna de vertebrados del Depasito de Conchuelas de Leisey es una de las mas diversas del Irvingtoniano en Norte Am6rica„ estando compuesta de por 10 menos 203 especies: 14 tiburones, 9 rayas, 50 peces teleosteos, 3 anfibios, 26 reptiles, 52 aves y 49 mamiferos. Leisey lA y I,cisey 3A son los mayores de cuatro sitios principales que constituyen la Fauna Local de los Dep6sitos de Conchuelas de Leisey. Leisey lA contiene vastas muestras de grandes mamiferos, en particular: los camalidos Palaeolama mirifica y Hemiauchenia macrocephala; dos especies de Equus; el mamut pninitivo Mammuthus hayi; los perezoses terrestres Paramylodon harlani y Nothrotheriops texanus; el tapir gigante Tapirus haysii; el pecari PlaMonus vems; el tigre dientes de sable grkil Smilodon gracilis; el oso de rostro corto Arctodus pristinus; y el dnido Canis edwardii. La fauna de grandes mamiferos dc Ikisey 3A es dominada por esqueletos asociados de juveniles de Hemiauchenia macrocephala, mientras que su diverso ensamblaje de microvertebrados contiene muestras importantes de peces de agua dulce, salamandras, culebras acuiticas, aves y pequeaos mamiferos. Los sedimentos en el Dep6sito de Conchuelas de Leisey son referidos a cuatro formaciones, cada una de las cuales ha producido f6siles de vertebrados. En la base de la secci6n estratig,Mica se encuentra una dolostona endurecida marr6n a gris claro, referida como Formaci6n Arcadia Un diente del caballo identificado como 'Megchippus" fern'us derivado de esta unidad es indicativo de una edad del Barstoviano temprano (principios del Mioceno medio). Lns sedimentos retrabajados encontrados encima de la Formaci6n Arcad ia contienen varios mamiferos terrestres, incluyendo los caballos Nannippus aztecus, Neohipparion eugstyle y Corn,ohippanon ingenuum cuya asociaciin es caracteristica de las faunas de fines del Hemphilliano temprano de Florida (Mioceno tardio). Las gravas fosfdlicas y piedrecillas esferoidales de metaquarzita en esta unidad son tipicas de la Formaci6n superior del Valle Hueso. Las mayores concentraciones de vertebrados 16siles en el Dep6sito de Conchuelas de Leisey ocurren en delgadas e irregulares capas de sedimentos ricos en materia organica distribuidos a lo largo de aproximadamente 7 m de camas arenosas de conchuelas marinas referidas como a la Formacidn Bermont, la cual se ubica sobre la Formaci6n Arcadia. El vasto ensamblaje de mamiferos terrestres encontrados en estas unidades orgdnicas en la Formaci6n Bermont pertenece al Irvingtoniano temprano (Pleistoceno temprano). Camas de conchuelas pertenecientes a la Formaci6n Fort Thompson ocurren en la secci6n Lkisey por sobre una inconformidad erosiva encima de la Formaci6n Bermont. Las camas de conchuelas de Fort Thompson contienen una fauna de mamiferos distintivamente mas jbven, e incluyen a: el bis6n Bison sp., la rata de algod6n Sigmodon hispidus y el tapir Tapirus veroensis. todos tipicos del Pleistoceno tardio (Rancholabreano). En un esfuerzo multidisciplinario para determinar la edad de la Formaci6n de Bermont en el Dep6sito de Conchuelas de Lcisey,,se han incorporado datos geocronol6gicos derivados de analisis paleomagnaticos; geocronologia de is6topos de estroncio; niveles del mar y biocronologia de moluscos y vertebrados. La biocronologia de moluscos indica una edad del Pleistoceno temprano o medio, mientras que la biocronologia de mamiferos es considerablemente mas - precisa, favorecien(jo fiertemente una edad del Pleistoceno temprano, de entre 1.6 y 1.0 Ma. Todas las muestras paleomagndticas de la Formaci6n Bermont en Leisey tienen una polaridad revertida y son referidas al Cron de Matuyama, indicando una edad mayor que 0.78 Ma. La seccitn de Bermont en Leisey no se correlaciona con el Subcron de Jaramillo de polaridad normal, de entre 1.07 y 0.99 Ma. Es tambi6n poco probable que las camas de Leisey hayan sido deposit'des durante la porci6n mas jdven de Matuyania. entre 0.99 y 0.78 Ma. La combinaci6n de datos de polaridad magnaica. biocronologia de mamiferos y niveles del mar indican fuertemente qup la Formaci6n Bennont en Lkisey es mas antigua clue 1.07 Ma y mas reciente que 1.55 Ma. La proporci6n de is6topos de estroncio 4 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 37, PT. I, NO. 1\ obtenidos de conchas de Chione cancellam (Mollusca) de L~isey indica una edad de entrely2 Ma. En base a la presencia de cinco g6neros desconocidos en Norte Am6rica antes del Pleistoceno(Nothrotheriops, Lutra, Castoroides, Palaeolama y Mammuthus), la fauna de 'Leisey es mhs jbven que otras faunas mejor conocidas del Irvingtoniano mh temprano de Florida (Plioceno mas tardio): Inglis 1Ayel Dep6sito de Conchuelas de De Soto. Cuatro roedores de LEisey difieren a nivel de especie de sus cons*neres de Inglis y De SNo·. Geomys pinens, Erethizon dorsatum, Sigmodon dbitinus y Ondatra annectens. Leisey tambitn carece de varios sobrevivientcs del Blancano, los cuales se encuentran en las otras dos faunas mas antiguas: la forma enana de Florida de Megolon,x leptostomus, Chasmaportheresossifragus, Trigonictis macrodon y Capromer>,x arizonensis. I.a presenda de numerosas espedes en Leisey desconocidas para desputs del Irvingtoniano temprano, tales como G(>protherium arizonae,Pachyarmatherium leiseyi, Holmesina floridanus, Nothrotheriops texanus, Sigmodon libitinus y Canis edwardil, constrifien aOn inds la edad de esta fauna, descartando una ¢dad del Irvingtoniano medio o masreciente. La fauna de mamiferos de Lcisey se correlaciona inds cercanamente con fines del Irvingtonianotemprano, entre aproximadamente 1.6 y 1.0 Ma Otras faunas de Florida de similar edad a Lcisey son: Haile164 Haile 214 Marna E16ctrica de Crystal River, Pool Branch, Mina Payne Creek Dep6sito de Conchuelas de Rigby y Punta Gorda. De estos sitios, Haile 16A es probablemente algo mds antiguo (entre1.6 y 1.3 Ma) en base a la ocurrencia de varios sobrevivientes de las faunas del Blancano tardio y el mas temprano Irvingtoniano de Florida, tales como Sylvitagus webbi, Geomyspropinetis y Trigonictis. Entre las faunas Irvingtonianas del oeste que son correlativas a Lkisey se incluyen a: Gilliland, Texas; Holloman, OklahonK Kentuck, Nash y Wathena en Kansas; Sappa, Nebraska; y Java Dakota del Sur. De entre estos sitios, Leisey comparte un nOmero mayor taxas de diagn6sticas con la Fauna Local de Gilliland, incluyendo 66ptotherium arizonae, una Holmesina /loridanus de tamafto medio, Nothrotheriops texanus, Canis edwardii, Tapirus haysii.y unMammuthus primmvo. 1.eisey y otrasfaunas del Irvingtoniano temprano son: mAs j6venes que faunas del Irvingloniano mAs temprano (2.0 a 1.6 Ma), tales como Rancho Curtis Arizona e Inglis lA y el Dep6sito de Conchuelas de De Solo en Florida; y: mas antiguas que faunas del Irvingtoniano medio (1.0-0.6 Ma), incluyendo la Formaci6n tipo de Irvington en California; Cudahy, Kansas; Fisura Conard, Arkansas; Cueva Cumberland, Maryland; Cueva Puerto Kennedy, Pennsylvania; Cueva Hamilton Virginia del Oeste; y el equivalente de Florida, la mina Mcleod Limerock La ocurrencia de mamiferos terrestres en unidades estuarinas, de agua dulce y terrestres dentro de la sequencia de camas de conchuelas predominantemente marinas y costeras de el sur de Florida peninsular pertenecientes al Plioceno tardio y al Pleistoceno (Camas de Pinecrest, Formaci6n Caloosahatchee, Formaci6n Bermont y Formaci6n Fort Thompson, en orden estratigr~fico ascendente) ha permitido una precisi6n en la determinacidn de su edad previamente imposible. Las Camas de Pinecrest que constituyen la unidad mAs superior de la Formaci6n Tamiami, contienen faunas de mamiferos terrestres del Blancano tardio (2.5-2.0 Ma), en base a la asociaci6n de Nannippus y una gran variedad de inmigrantes Neotropicalea, cue induyen Dasypus, Holmesina, Gtyptotherium, Glosaotherium, Eremotherium y Neochoerus. Las faunas del Blancano lardio de Florida derivadas de las Camas de Pinecrest, o encontradas en asociaci6n con faunas de moluscos de Pinecrest incluyen el Dep6sito de Conchuelas de Macasphalt, el Dep6sito de Conchuelas de Acline, St Petesburg Times, Rio Kissimmee, Canal Brighton y Lzhigh Acres. Las faunas de vertebrados de la Formaci6n sobrepuesta de Caloosahatchee carecen de formas Blancanas tipicas, induyendo Borophagus, Nannippus, Equus (Dolichohippus) y Rhynchotherium, e induyen taxas tipicas del Irvingtoniano mas temprano (2.0-1.6 Ma), tales como Inglis lA I.as faunas mas ricas del Irvingloniano mb temprano de la Formaci6n Caloosahatchee en el sur de Florida son el Depuito de Conchuelas de De Soto y el Dep6sito de Conchuelas de Forsberg, Las faunas de vertebrados de la Formaci6n Bermont son de fines del Irvingtoniano temprano (1.6-1.0 Ma) y son tipificadas por el Dep6sito de Conchuelas de Lcisey, asi como tambi6n el Dep6sito de Conchuelas de Rigby, la Planta El6ctrica de Crystal River y Punta Gorda. Las faunas de vertebrados asocia€las con la Formaci6n Fort Thompson contienen tipicamente Bison y otras taxas caracteristicas de la Edad de Mamiferos Terrestres del Rancholabreano. MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 3 INTRODUCTION A remarkable concentration of early Pleistocene (Iningtonian) vertebrate fossils was discovered by Frank Garcia in July 1983 after it was uncovered by a dragline during routine mining operations at the Leisey Shell Pit. This rich bone bed, designated Leisey Shell Pit 14 is located about 7 lan southwest of Ruskin in Hillsborough County, Florida (27°42'N latitude, 82°30'W longitude). Field teams from the Florida State Museum (now the Florida Museum of Natural History) and a large volunteer crew organized by the Tampa Bay Mineral and Science Club excavated the Leisey Shell Pit lA Site almost continuously from April to September 1984. The total amal extent of the bone bed was approximately 2000 mp about 1300 m2 ofwhich was excavated during 1984, whereas 700 m2 had been dug by avocational paleontologists in 1983. All fossils recovered in 1984 are housed in the Vertebrate Paleontology Collection of the Florida Museum of Natural History, University ofFlorida (UF). Frank Garcia discovered a second rich concentration of vertebrate fossils at Leisey in November 1986, this time in a newly opened pit on the north side of Gulf City Road, only about 0.5 km north of Leisey lA (Fig. 1). This site, Leisey Shell Pit 34 was dug by Garcia and a volunteer field crew, as well as UF personnel, between November 1986 and February 1987. Although not as rich as Leisey lA in numbers of species or individuals of large mammals, Leisey 3A in many ways complements the fauna from the original site, particularly in the comparatively large samples of freshwater and terrestrial microvertebrates. The most characteristic aspect of the Leisey 3A site is the abundance of the long-limbed 11ama, Hemiauchenia macrocepha/a, especially juvenile individuals. The Lcisey Shell Pit Local Fauna (LF), named by Hulbert and Morgan (1989), is composed of vertebrate fossils collected from Leisey Shell Pit lA and 34 as well as two other smaller sites, Leisey Shell Pit lB and 3B. The four named Leisey sites are located in two nearly contiguous shell pits mined by the Leisey Shell Corporation. These concentrations of vertebrate fossils occur in thin layers or lenses throughout a stratigraphic interval of about 7 m within the predominantly marine shell beds of the Bermont Formation. The two shell pits, along with a third pit owned by the same corporation, have been assigned numbers (Leisey Shell Pit 1-3) and each major concentration of bones within a numbered pit has been given a letter designation. This is the standard system now used by the UF vertebrate paleontology program for naming and numbering specific localities within commercial quarlying operations. For example, Leisey Shell Pit lA (shortened to Leisey lA for convenience) specifies only those fossils recovered from the large site collected in 1983-1984. Fossils not from designated sites, often those collected 6 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 37, Fr. I, NO. 1 A / GULF CITY ROADLEISEY 3 LEISEY 2 <'~_- -~ ~ 18 1 A ~ COCKROACH BAY ROAD HAYES BAYOU COCK OACH SUN CITY BAY 0 1 MILE 0 1KM r B | HILLSBOAOUGH COUNTY LEISEY SHELL PITS ..0 0. Figure 1. (A) Map of the I.cisey Shell Pit region showing the location of the three Leisey pits and the four vertebrate-bearing sites mentioned in the text (B) Map showing general location of the Leisey Shell Pit in Florida and Hillsborough County. MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 7 from excavation spoil piles, are assigned a quarry number, but not a letter (e.g. Leisey Shell Pit 2). This supercedes a previous system that used roman numerals to designate quarry numbers (e. g. Coleman IIA is now Coleman 2A). The maps in Figure 1 show the location of the three Leisey Shell Pits in southwestern Hillsborough County. Leisey 1 is located in the SWK of section 15 and Leisey 3 is in the S!,2 of the NW'/4 and the SM of the NE'h of section 15, T32S, RlSE, Ruskin Quadrangle (USGS 7.5 minute series, 1981). Leisey 2 is in the SEW of section 16, T32S, R18E, Cockroach Bay Quadrangle (1969). The exact coordinates of the two Leisey sites that have produced the vast majority of the vertebrate fossils upon which the papers in this volume are based are as follows: Leisey Shell Pit lA (NWW, SEM, SW'A Sec. 15, T32S, RISE) and Leisey Shell Pit 3A (SWK, SEK, NWA Sec. 15, T32S, RlSE). Leisey lA and 3A were completely excavated in 1983-1984 and 1986-1987, respectively, and have since been destroyed by mining operations. Although Leisey lA and 3A are the largest and richest sites in the Leisey Shell Pit, there are numerous other Leisey sites, three of which have been given separate designations Beisey 18, 1(, and 38; see Fig. 1). Because all three Leisey pits are less than 1 km inland from Tampa Bay to the west and are below 3 m in elevation, the local water table in this region is very near the ground surface. Most of the important bone concentrations were actually below mean sea level (i.e. more than 3 m below the present ground surface). Like most other commercial shell mining operations along Florida's Gulf Coast, the water levels in the Leisey pits are maintained at artifically low levels by pumping so that mining can be conducted above water. The Leisey 1 and 2 pits are no longer being actively mined and have been allowed to fill with water. Mining ceased at Leisey 3 in 1992 and it will subsequently flood as well. There are no in-place samples of vertebrate fossils from Leisey 2 in the UF collection. Leisey 2 is also the only one of the three pits that contains a substantial number of Rancholabrean fossils, although Irvingtonian vertebrates are common in this pit as well. We have been unable to confidently establish the age of many of the specimens from Leisey 2 because they were collected from spoil piles, and thus have excluded them from this analysis and from the Leisey Shell Pit LF. The Leisey Shell Pit LF is one of the richest early Pleistocene (Irvingtonian) vertebrate faunas in North America, both in terms of numbers of species and individuals. The vertebrate assemblage from Leisey is composed of 203 species, including 23 species of cartilaginous fish (14 sharks and 9 rays), 50 species of bony fish, 3 amphibians, 26 reptiles, 52 birds, and 49 mammals. Table 1 provides a complete vertebrate faunal list for the Leisey Shell Pit LF. To date, over 15,000 specimens of vertebrate fossils have been catalogued from the Leisey Shell Pit LF, the majority of which are from Leisey lA. Most of the mammal papers in this volume are based primarily on material from Leisey lA. However, Leisey ]A has a much richer vertebrate microfauna than does Leisey lA, and consequently the 8 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 37, Pr. I, NO. 1 papers on fish, ami)hibians and reptiles, birds, and small mammals contain considerable data on fossils from Leisey 3A. ACKNOWLEDGMENTS This review represents a compilation of data from a variety of sources, including field studies atL,eisey and other Florida Pli,-ne and Pleistocene sites by ourselves and many others study of the extensivecollections of Plio-Pleistocene vertebrate fossils housed in the Florida Museum of Natural History, md acomprehensive review of the literature on this topic. We 1hank the many contributors to this volume whopermitted us to briefly surnmarize their work so that we could provide a complete vertebrate faunal list and areasonably comprehensive review ofthe geochronology and biochronology of the L~eisey Shell Pit. We areespecially grateful to the authors of the papers on the various vertebrate groups who allowed us to combinethe individual faunal lists from their papers in order to produce a complete vertebrate faunal list for the Leisey Shell Pit I MAI FA,inA (Table 1). As with all of the contributors to this volume, we are very grateful to the personnel of the Lcisey ShellCorporation for all of'their support and to the hundreds of volunteers who worked with the Florida Museumof Natural History in the excavation of the Ikisey Shell Pit Sites IA and 3A The Preface to this volumeshould be consulted for more extended acknowledgments regarding the assistance provided by the LeiseyShell Corporation and the dedicated volunteer crews co-ordinated by the Tampa Bay Fossil Club. We would also like to thank several ofour colleagues, including Steven D. Emslie, David Kendrick, Arthur R Poyer, and Ann E. Pratt, who over the past ten yearshave participated "above and beyond the call of duty" inthe excavation of several of the critically impoitant sites discussed here, in particular Izisey, Macasphalt ShellPit, Haile 7C. and Haile 21A. The following individuals donated important specimens of vertebrate fossitsto the UF collection from various Florida Blancan and Irvingtonian sites: Stephen Beck, D. J. Bethea, Lelia and William Brayfield, the late Howard H. Converse, Jr., Daniel Delgado, Ralph "Tony" Esteveg Wayne Filyaw. Frank A Garcia, George Heslep, Mitchell Hope, Muriel Hunter, Eric Kendrew, the late Philip Kinsey, Larry Martin, Thomas Missimer, James Penderg,"aft, Brian Ridgway, Barbara Toomey, James Toomey. Reed Toomey. the late Benjamin I. Waller, Suzan Watts, and Steven Wilson. Field work at Leiseyand Macasphalt and curation of vertebrate fossils from these and several other sites discussed here was supported by National Science Foundation Grants EAR 8708045, BSR 8314649 and BSR 8902822. This is University of Florida Contribution to Paleobiology Number 401. ABBREVIATIONS UF-Vertebrate Paleontology Collection, Florida Museum of Natural History. University of Florida Gainesville. LF - Local Fauna NALMA - North American Land Mammal Age. Ma - Mega-anna millions ofyears before present on the radioisotopic time scale. ka - kilo-anna thousands ofyears before present on the radioisotopic time scale. cm - centimeter. m - meter. km - kilometer. T - Township. R - Range. P/p - upper/lower premolar (e.g. P# is an upper fourth premolar) M/m - upper/lower molar (e.g. ml is a lower first molar). MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 9 Tablet. Vertebrate faunallist ofthe early Irvingtonian Leisey Shell Pit Local Fauna, Hillsborough County, Florida. This list has been compiled from the individual papers on the vertebrate groups published elsewhere in this volume. Within each family the genera and species are listed in alphabetical, not phylogenetic, order. Several species of amphibians and reptiles (Meylan, this volume) and birds (Ernslie, this volume) are excluded from this list because they were identified only from Leisey 2 which contains a mixed assemblage of Irvingtonian and Rancholabrean tan Chondrichthycs Batoidea Pristidae Pristis sp. Dasyatidae Dao,ans--2 species Myliobalidae Aetobatui narinari Mytiobatis sp. Rhinoptera bonams Rhynchobatidae Rhynchobatux sp. Galeomorpha Orectolobidae Ginglymostoma cirratum Ginglymostoma serra Odontaspidae Odontaspis taurus Lamnidae Carcharodon carcharias Imrus hastalis Imrus oxyrinchus Hemigaleidae Hemipristis serra Carchadinidae Carcharhinua acronotus Carcharhinus leucas Carcharhinua limbatus Carcharhinua obscums Carcharhinus plumbeus Galeocerdo cuvieri Negaprion brevirostrix Rhizoprionodon terraenovae Sphyrna mokarran Osteichthyes Semionotiformes L/pisoslcidae Atractosteus spatula Lepisosteus cf. L. oculatus Lepisosteus osseus 10 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 37, PT. f, NO. 1 Table l Continued Amilformes Amiidae Amia calva Elopiformes Elopidae Elops saurus Megalops atlanticus Anguilliformes Anguillidae Anguilla rostrata Clupeiformes Clupeidae genus and species indet Salmoniformes Esocidae Esor sp. Cypriniformes Cyprinidae Notemigonus chrysoleucas Catostomidae Erimyzon c£ E. sucetta Situriformes Ariidae Ariua felis Bagre marinus Ictaluridae Ameiurus natalis Ameiurus nebulosus Batrachoidif6rmes Batrachoididae Opsanus sp Alhedndonnes Atherinidae cf.Menidia sp. Cyprmodontidae Cyprinodon variegatus cf. Floridichthyes sp Fundulus cf. F. grandis Fundulus seminolis Fundulus majalis Exocoetidae cf. Hyporhamphus sp. Perciformes Carangidae Caranx hippos cf. Trachinotu3 sp Centrarchidae I.epomis cf. L. auritus Lepomis guloms Lepomis microlophus MORGAN & HULBERT: OVERVIEW OFTHE LEISEY SHELL PIT LOCAL FAUNA 11 Table 1 Continued Microptents salmoides Pomoxis nigromaculatus Centropomidae Centropomus sp Ephippidae Chaetodipterus jaber Labridae Ldchnolaimus marimus Mugilidae Mugil sp. Percichthyidae cf Morone sp Sciacnidae Bairdiella c[. B. chrysoura Cynoscion cf C nebulosus Micropogonias undulatus Pogonias cromis Sciaenops ocellatus Sparidae Archosargus probatocephalus Calamus sp. Lagodon rhomboides Sphyraenidae Sphyraena barracuda Pleuronectiformes Bothidae genus and species indeL Tetraodontiformes Balistidae Balistes so Diodontidae Chilomycterus gchoepA Diodon sp Ostraciidae Lacroph,ys sp. Amphibia Urodela Sirmidae Siren lacertina Anura Bufonidae Bufo ci B. terrestris Ranidae cf Rana sp Reptilia Crocodylia Alligatoridae Alligator minissippiensis 12 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 37, PT. I, NO. 1 Table l Continued Squamata Lacertilia Anguidae Ophisaurus compressus Serpentes Boidae d Tropidophis sp Colubridae Coluber sp./Masticophis sp. Elaphe 4 E. obsoleta Farancia * Lampropellis getulus Nerodia ct N. fasciata Regina cf. R. alleni cf. Thamnophis sp. Viperidae Agkistrodon piscivorous Crotalus cf. C. adamanteus Sistrurus miliarius Testudines Cheloniidae Caretta carettal Chelonia mydas Chelydridae Chetydra serpentina Macroclemys temmincki Testudinidac Gopherus polyphemus Heaperotestudo crassiscutata Hesperotestudo mlynarskii Emydidae Pseudemys sp. Terrapene carolina Trachemys scripta Kinostemidae Kinosternon sp Trionychidae Apaloneferox Aves Gaviiformes Gaviidae Gavia concinna Gavia immer Podicipediformcs Podicipedidae Podiceps sp. Podilymbus podiceps MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 13 Table 1 Continued Pelecaniformes Pelecanidae Pelecanus cf. P. erythrorhynchos Phalacrocoracidae Phalacrocorax-2 species Anhingidae Anhinga anhinga Anhinga sp. Ciconiiformes Ardeidae Ardea sp Casmerodias albus Egretta cf. E. tricolor Threskiornithidae Ajaia chione new spedes Eudocimus leiseyi new spedes genus and sp. indet Ciconiidae Ciconia maltha C,conia sp Teratornithidae Teratornis cf. T. incredibilis Teratomis merriami Vulturidae Gymnogyps kofordi Anseriformes Anatidae Anabernicula gracilenta Anas americana Anas crecca Anas platyrhynrchos Aythya *inis Aythya americana Aythya collans Aythya marila Branta canadensis Branta dickeyi Bucephala albeola Cygnus buccinator Mergus serrator 0 lor sp Somateria ct S. spectabilis Accipitriformes Accipitridae Amplibuteo sp Aquila sp. Buteo 4 B. lineatus Buteo sp 14 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 37, PT. I, NO. 1 Table 1 Continued Galliformes Phasianidae Colinus sp. Meleagris leopoldi/M. anza Gruiformes Rallidae Fulica americana RaUus sp Gruidae Grus canadensis Grus sp. Charadriiformes Recunirostridae Recurvirostra sp. Scolopacidae Limosa cf. L. fedora Alcidae gen. et sp. indeL Phoenicopteridae Phoenicopterus copei Phoenicopterui ruber Strigiformes Strigidae Bubo virginianus Passeriformes Co:vidae Corvus sp. Mammalia Xenarthra Dasypodidae Dasypus bellus Pachyarmatherium leisey, new genus and species Pampatheriidae Holmesina jloridanus Glyptodontidae Glyptotherium arizonae Megalonychidae Megalonyx wheatleyi Mylodontidae Paramylodon harlani Megatheriidae Eremothenum n. sp. Nothrotheriops texanus Insectivora Soricidae Blarina cf. B. carolinensis Carnivora Canidae Canis armbrusteri MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 15 Table 1 Continued Canis edwardii Urocyon sp. Phocidae Monachus tropicalis Procyonidae Procyon asp. Ursidae Arctodus pristinus Mustelidae Mustela frenata Lutra canadensis Spilogale putorius Felidae Homothenum n. sp. Lynx rujits Miracinonyx inexpectatus Smilodon gracilis Rodentia Castoridae Castoroides leiseyorum new species Geomyidae Geomys pinetis Erethizontidae Erethizon dorsatum Hydrochaeridae Neochoerus sp. Muridae Ondatra annectens Pedomys n. sp Podomys n. sp. Sigmodon tibilinus Synaptomys sp. Lagomorpha Leporidae Lepus cfL. townsendii Sylvilagus floridanus Perissodactyla Tapiridae Tapirus haysii Equidae Equus "fraternus" Equus "lei*'" Equus (Hemionus) n. sp Artiodactyla Tayassudiae Mytohyus fossilis Platygonus vetus Camelidae Hemiauchenia macrocephal03 Palaeolama mirifica 16 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 37, PT. I, NO. 1 Table l Continued Cervidae Odocoileus virginiamis Cetacea Delphinidae cf. Stenetta sp 6 Turnops sp. genus and species indeL Sirenia Trichechidae Trichechus sp. Proboscidea Mammutidae Mammut americanum Gomphotheriidae Cuvieronius tropicus Elephantidae Mammuthus hayi 1 Collected Som Fort Ihompson Form~on above Leisey lA bone bed- 2 Webb and Stchli (this vohrme) use H ze)„wiren,13 for the Lcisey sample of Hemiwchnia. DEFINITION OF CHRONOLOGIC AND BIOCHRONOLOGIC BOUNDARIES. In this section, we discuss the age of the Pliocene/Pleistocene boundary and the subdivisions of the Pleistocene, as well as the definitions and subdivisions of the Blancan and Irvingtonian Land Mammal Ages used in this study. This is necessitated by recently published changes to the geologic and geomagnetic polarity time scales (Fig. 2). The Pliocene/Pleistocene boundary is now generally placed at 1.64 Ma above the top of the Olduvai Normal Subchron of the Matuyama Chron (Berggren et at. 1985; Harland et al. 1990). This is younger than the 2.0 Ma date for this boundary recognized until recently by most North American vertebrate paleontologists (e.g. Kurt6n and Anderson 1980). The older 2.0 Ma date was convenient because it also approximated the boundary between the Blancan and Irvingtonian Land Mammal Ages. With the recognition of a younger Pliocene/Pleistocene boundary, the earliest portion of the Irvingtoman (the interval between 2.0 and 1.6 Ma) is not Pleistocene as has been widely used, but rather latest Pliocene. The Pleistocene Epoch is subdivided into the early, middle, and late Pleistocene (Fig. 2). The early Pleistocene begins at 1.64 Ma and ends at the boundary between the Matuyama and Brunhes chrons at 0.78 Ma. The middle MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 17 MA AGE NALMA GEOMAGNETIC POLARITY SOUTH FLORIDA TIME SCALE LITHOSTRATIGRAPHY 00 20,3 =- RANCHO- - FORT THOMPSON FM. 0.2 LABREAN f 04 2 2 OA w iii Z Ul E 0.8 0 -078 ~ 10 1.0 - ~ » ~ -1II~A-RA~LLO 1.2 Z 5 f BERMONT FM.E . 16- MATUYAMA 1.6 E -5 OLDUVAI CALOOSAHATCHEE FM. . Ul Z 2.0 - UJ 0 Z 0 4 22 2 %% UNION PINECREST BEDS 14 . Figure 2. Chart depicting chronologic correlation between units of the geologic time scale (after Harland et al. 1990), North American Land Mammal Ages, the geomagnetic polarity time scale (after Valet and Meynadier 1993), and southwestern Florida stratigraphic formations. Pleistocene covers the time period from the beginning of the Bnmhes Chron at 0.78 Ma until the onset of the last (Sangamonian) interglacial at 132 ka. The late Pleistocene extends from about 132 ka to the Pleistocene/Holocene boundary at 10 ka. These subdivisions of the Pleistocene follow Harland et al. (1990), as adjusted for the updated geomagnetic polarity time scale of Valet and Meynadier (1993). Vertebrate paleontologists do not all agree on the definitions and boundaries of the late Pliocene and Pleistocene North American Land Mammal Ages (NALMA), including part of the Blancan and all of the Irvingtonian and Rancholabrean. The subdivisions of these three NALMA are even less well understood. The two most recent attempts to define and subdivide the Irvingtonian and Rancholabrean (Lundelius et al. 1987-based on all mammal groups; Repenning 1987-based only on arvicoline rodents) are not in complete agreement. 18 - BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 37, PT. I, NO. 1 Therefore, it is important to establish our criteria for defining and subdividing these NALMA, particularly the Irvingtonian since this is the age in which the Leisey Shell Pit LF occurs. Repenning (1980; 1987) proposed a biochronology for the Blancan through the Rancholabrean NALMA based on evolutionary stages and immigration events of arvicoline rodents, more often termed "microtine" rodents in the extensive literature on the fossil history of this group. Our use of the term "arvicoline" in this paper is synonymous with the use of microtine by Repenning (1987) and other authors. Among the 74 Blancan and Irvingtonian aivicoline faunas discussed by Repenning (1987), only Cumberland Cave in Maryland is located in eastern North America (i.e., east of the Mississippi River). Repenning and Grady (1988) have since described an extensive middle Irvingtonian arvicoline fauna from Hamilton Cave, West Virginia. The published arvicoline fauna from the late Irvingtonian Coleman 2A LF, Sumter County, Florida (Martin 1974; Frazier 1977) was not mentioned by Repenning. Arvicolines are principally a temperate group Of rodents, and consequently they have a limited distribution in subtropical regions such as Florida. With only three species presently occurring in the state, Microtus pennsylvanicus, Pitymys pinetorum, and Neojiber alleni, Florida has one of \he poorest arvicoline faunas known from anywhere in the continental United States. Arvicoline rodents are unknown from Florida Blancan vertebrate faunas and are uncommon in most Pleistocene sites. Nonetheless, arvicolines are now known from eight Irvingtonian sites in Florida. A mammalian biochronology that uses many different types of taxa, in addition to arvicoline rodents (e. g., Lundelius et al. 1987), is much more applicable in Florida. The Blancan NALMA covers the time interval between 4.5 and 2.0 Ma. Lundelius et al. (1987) divided the Blancan into the early, middle, and late Blancan, whereas Repenning (1987) recognized five Blancan subdivisions (Blancan I-V) based on arvicoline rodents. Only the late Blancan of Lundelius et al. (1987) or Blancan V ofRepenning (1987) is discussed here, as early and middle Blancan (Blancan I-IV) land mammal faunas are unknown from Florida (Morgan and Ridgway 1987). The beginning of the late Blancan (about 2.5 Ma) was marked by the formation of the Panamanian Land Bridge and the first abundant appearance in North America of Neotropical immigrants, as well as the arrival of several genera ofEurasian immigrants. The late Blancan immigration events from both South America and the Old World probably were responses to major continental glaciation in the Northern Hemisphere and correspondingly low sea levels between about 3.0 and 2.5 Ma (Shackleton and Opdyke 1977). Typical Blancan genera found in Florida faunas referred to this NALMA include Borophagus, Trigonictis, Nannippus, Equus (Dolichohippus), and Rhynchotherium. Neotropical mammalian genera that first appear in Florida during the late Blancan include the xenarthrans Dasypus, Glyptotherium, Holmesina, Eremotherium, and Glossotherium and uie ca,Aomorph rodents MORGAN & HULBERT: OVERVIEW OFTHE LEISEY SHELL PITLOCAL FAUNA 19 Erethizon and Neochoerus, as well as the giant phororhacid bird Titanis. The co- occurrence or overlapping range zone of Mannippus and these South American immigrants defines a narrow time interval between 2.5 and 2.0 Ma, after the formation of the Panamanian isthmus and the beginning of the Great American Interchange, but before the extinction of Nannippus (Galusha et al. 1984; Lindsay et al. 1984; Morgan and Ridgway 1987). The Blancan/Ilvingtonian boundary is usually placed near the base of the Olduvai Subchron (Lundelius et al. 1987; Repenning 1987), that is now dated at 1.95 Ma (Valet and Meynadier 1993). Lundelius et al. (1987) did not precisely define this boundary on faunal grounds, but described a transitional period between about 2.0 and 1.6 Ma during which late Blancan faunas gradually changed into early Irvingtonian faunas. However, Repenning (1987) noted a major change in arvicoline rodent faunas at the Blancan/Irvingtonian boundary (which he placed at 1.9 Ma), with the arrival of a number of Old World immigrants at this time, as well as the first abundant occurrence of taxa with unrooted teeth. The earliest Irvingtonian marks the first appearance of arvicoline rodents in the Florida fossil record (Ondotra idahoensis, Atopomys salvelinus). The ages of the late Blancan Borchers LF (Kansas) and earliest Imingtonian Curtis Ranch LF (Arizona) are the primary basis for determining the date of the Blancan/Ifvingtonian boundary (Lundelius et al. 1987:217). Borchers is located in the top of and just above the Pearlette B ash bed, which has a K-Ar date of 2.01 Ma (Izett 1981). Curtis Ranch stratigraphically lies just below the base of the Olduvai Subchron in geomagnetically reversed sediments. Valet and Meynadier (1993) show a date of about 1.95 Ma for the base of the Olduvai. These dates tightly constrain the boundary between the Blancan and Irvingtonian to the interval 2.01 to 1.95 Ma, or approximately 2.0 Ma (Fig. 2). A somewhat younger age for this boundary, 1.9 Ma, was used by Lundelius et al. (1987) and Repenning (1987), because the then accepted age for the base of the Olduvai Subchron was 1.88 Ma. Lundelius et al. (1987) characterized the Irvingtonian by the first appearance of Equus sensu strkto (s.s.), Euceratherium, Mammuthus, Smilodon, and Microtus, among others. Smilodon is now known to be present in at least four late Blancan faunas in Florida (Berta 1987). Mammuthus does not reach North America from the Old World until sometime after 1.6 Ma, and thus its first appearance in the New World is well above the Blancan/Irvingtonian boundary (Lindsay et al. 1984; Lundelius et al. 1987). Since the Irvingtonian covers the latest Pliocene and much ofthe Pleistocene (between 2.0 and 0.3 Ma), it is useful to subdivide this NALMA into smaller time units. Lundelius et al. (1987) recognized three subages of the Irvingtonian: early Irvingtonian (Sappan), middle Irvingtonian (Cudahyan), and late Irvingtonian (Sheridanian). We use the terms early, middle, and late for these three subdivisions following the terminology generally applied to other NALMA (Woodburne 1987). We furthermore find it convenient to recognize four subdivisions of the In,ingtonian (earliest, late early, middle, and late), at least for 20 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 37, PT. 1, NO. 1 our biochronologic analyses ofFlorida fossil faunas. The boundaries between these four subdivisions of the Irvingtonian are not well constrained by geochronologic data in Florida, and thus should be considered approximate and provisional. The boundary between the earliest and late early Irvingtonian is set at 1.6 Ma (Fig. 2), to approximate the Plio-Pleistocene boundary. At least some late early Irvingtonian faunas in Florida come from reversely magnetized sediments that are correlated to the portion of the Matayuma Chron between the Olduvai and Jaramillo Subchrons (between 1.79 and 1.07 Ma; Valet and Meynadier 1993). These faunas also most closely resemble those from the Great Plains (Gilliland, Holloman, Sappa) that are dated at 1.5 to 1.3 Ma (see discussion below). The middle Irvingtonian of our usage is the equivalent of the Cudahyan Subage of Lundelius et al. (1987), and approximates the Irvingtonian II of Repenning (1987). In the Great Plains, Cudahyan faunas underlie the Pearlette O ash (0.61 Ma; Izett 1981) and overlie the Pearlette S ash (1.27 Ma; Izett 1981). The oldest faunas included in the middle Irvingtonian were deposited during the portion of the Matayuma Chron that postdates the Jaramillo, an interval now dated at 0.99 to 0.78 Ma (Valet and Meynadier 1993). These include portions of the Alamosa LF of Colorado (Rogers et al. 1985), and the Irvington LF and Centerville Beach LF of California (Lindsay et al. 1975; Repenning 1987). We therefore suggest that the age of the top of the Jaramillo Subchron, ca. 1.0 Ma, be used as the boundary between the early and middle Imingtonian. The Cudahy LF of Kansas is associated with the 0.61 Ma Pearlette O ash, and thus forms a convenient upper boundary for the middle Irvingtonian (Lundelius et al. 1987). The late Irvingtonian (or Sheridanian) includes faunas younger than 0.6 Ma, but which predate the dispersal of Bison into North America, the event that defines the base of the Rancholabrean. Unfortunately, this dispersal event is poorly constrained, and estimated to lie between 0.5 and 0.2 Ma (Lundelius et al. 1987). We therefore use the approximate midpoint of this range, 0.3 Ma, for the Irvingtonian/Rancholabrean boundary, with the expectation that furture work will more precisely document the arrival ofBison in North America. The 0.3 Ma date also corresponds to the beginning of the late middle Pleistocene, and the onset of a major period of continental glaciation (Richmond and Fullerton 1986). GEOLOGY AND GEOCHRONOLOGY OF THE LEISEY SHELL PITS Geologic Descriptions of Leisey Strata.-Sediments exposed by mining operations at the Leisey Shell Pit are tentatively referred to four formations, each of which has produced vertebrate fossils, as well as a surficial layer of unconsolidated sand (Fig. 3). In this section we first describe the local geology and stratigraphy of the three Leisey Shell pits, particularly Leisey 1 and 3, emphasizing the bone-rich MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 21 COMPOSITE SECTION COMPOSITE SECTION LEISEY SHELL PIT I LEISEY SHELL PIT 3 HILLSBOROUGH CO., FLONDA HILLSBOROUGH CO., FLORIDA depth below ground surface (m) -0 0.4 4 modern soil zone Ul 0.4 m, modem soll zone (removed) 1.3 m, unconsolldated r . 2.4 m, quartz sand ~ B er m on t F or m at io n mp · Un dlf f UPPER SHELL BED 5 1.5 m, buff to cream, - - sandy. massive shott < 2 bed_ UPPER SHELL BED ~ 0 4 d[!Y •andd BONABED - 2 i3.0 m, buH, sandy, E s LOWER SHELL BED massive shell bed B N 3001513ld3.3 m, cream to bluish, . Ul sandy, massive shell bed 0.4 m, shelly,dolorn., -hard layer" ~ J<* shi~, mu€~y, BO~E BE[i - ~ . - -- 1.0 m, dark, sandy mud; 5 5 freshwater shells; bones LOWER SHELL BED ~ i4.3 m, blulsh, sandy, massive shell bed 10 ~dZrk, sandy 2\ inur! , modern mean sea level tan, hard, massive, phosphatic dolomite 8 2 0 ii 1 Figure. 3. Stratigraphic sections of the Leisey Shell Pit lA and 3A sites Hillsborough County, Florida measured by the authors in 1984 and 1986. See text f6r detailed description oflhe sections. 22 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL« 37, Fr. I, NO. 1 lenses. We then summarize the geochronology of the Leisey strata based on vertebrate biochronology and data from other papers in this volume, including invertebrate biostratigraphy, paleomagnetics, and strontium isotope stratigraphy. At the base of the stratigraphic section exposed in the Leisey Shell pits is a well-indurated, tan to light gray, clayey, phosphatic dolostone. Identifiable invertebrate fossils have not been recovered from this unit, but waterworn sirenian and cetacean fossils are fairly common. The top of this unit is very uneven and represents a major erosional unconformity. The most biostratigraphically-useful fossil found in 1his bed is a well preserved, slightly worn lower molar (ml or m2) of a merychippine-grade horse (UF 53819). The crown height and enamel pattern of UF 53819 closely matches those of lower molars recovered from the Arcadia Formation at Nichols Mine in Polk County, located about 35 km northeast of Leisey. Hulbert and MacFadden (1991) tentatively referred this sample to "Merychippus" tertius, a species otherwise known from the late Hemingfordian Oate early Miocene) of Nebraska. However, other mammals in the Nichols Mine fauna principally rodents, indicate a slightly younger, very early Barstovian (earliest middle Miocene) age (Pratt, Morgan, and Poyer in prep.). Scott (1988) stated that the Arcadia Formation is widespread throughout the subsurface of southern Florida including southwestern Hillsborough County, and his description of its lithology agrees well with that of the basal Leisey stratum. Accordingly, the lowermost bed at Leisey is referred to the Arcadia Formation of the Hawthorn Group. The Bone Valley Formation unconformably overlies the Arcadia Formation over a wide area in central Florida (Scott 1988). We use the name Bone Valley Formation in its traditional, broad sense, and as the equivalent of the Bone Valley Member of the Peace River Formation of Scott (1988). As mapped in the subsurface by Scott (1988, figs. 36, 53), the Bone Valley Formation rapidly thins in western Hillsborough and Manatee counties, and is absent in some sections. The Bone Valley Formation was not observed in outcrop at Leisey, but several land mammals characteristic of this unit were recovered from a reworked zone on top of the Arcadia Formation at the north end of Leisey Pit 1 (Fig. 1). This site, called Leisey 1C, contained phosphate pebbles and gravel and spheroidal metaquartzite pebbles, all typical of the uppermost unit of the Bone Valley Formation (Pirkle et al. 1967). Vertebrate fossils from Leisey IC are heavily waterworn and a dull black color. Their preservation differs considerably from bones recovered from the overlying shell beds. Both marine and terrestrial tan are represented (Hulbert and Morgan 1989). As is typical in low-elevation deposits of the Bone Valley Formation in southwestern Florida isolated horse teeth are the most common terrestrial vertebrate fossils, and the most useful biochronologically. Three equid species are recognized from Leisey 1 C on the basis of diagnostic dental character states: Nannippus aztecus (UF 43564, 107531, 107532; see Hulbert 1990 for use of N. aztecus instead of N. minor): Neohipparion eurystyle MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 23 (UF 107528); and Connohipparion ingenuum (UF 107529, 107530). The chronologic range of, the first two species is late early Hemphillian through very late Hemphillian (7.0 to 4.5 Ma; Hulbert 1987, 1990). The range of the latter is early Clarendonian through late early Hemphillian (11.5 to 6 Ma; Hulbert 1988b). Their concurrent range is thus constrained to the late early Hemphillian (very late Miocene). Similarly preserved, low-elevation occurrences of fossiliferous Bone Valley-type deposits are also known from Manatee (Port Manatee, Manatee County Dam, and Braden River sites) and Sarasota (Lockwood Meadows) counties. Based on the biochronology of their equid faunas these five Gulf Coastal sites, termed the Manatee Fauna (Morgan 1994), are correlated with the late early Hemphillian (approximately 7 Ma) Withlacoochee 4A and Moss Acres local faunas from Marion County in northern Florida (Hulbert 1988b), and were probably deposited just prior to the latest Miocene (Messinian) eustatic drop in sea level that occurred between 6.7 and 5.2 Ma (Webb and Tessman 1968; Haq et al. 1987; Morgan 1994). Leisey 1C represents the northernmost occurrence of these low elevation, Bone Valley-type deposits along the Florida Gulf Coast. A rostral or mandibular fragment of the long-beaked dolphin Pomatodelphis (UF 142238) and four auditory bullae of small cetotheriid mysticetes (UF 88614, 107524, 142240, 142246) from Leisey 1 closely resemble specimens from middle and late Miocene sites elsewhere in peninsular Florida, in particular the lower unit of the Bone Valley Formation of Polk and adjacent counties (Morgan 1994). Abundant large, dense sirenian ribs (UF 142241-142243) from Leisey 1 probably pertain to the dugongid Metaxytherium, although the ribs are not specifically diagnostic. The Leisey marine mammal fossils were found near the base of the section in the Leisey 1 Pit, but were collected out of stratigraphic context and thus could conceivably belong to either the Barstovian or Hemphillian faunas. The Metaxytherium-Pomatodelphis-cetothere assemblage (Morgan 1994) characterized Florida marine mammal faunas from the late early Miocene (late Hemingfordian) through the late Miocene (late early Hemphillian). ,An approximately 8 m thick sequence of massive marine shell beds rests upon the eroded surface of the Arcadia Formation at Leisey (Fig. 3). Reworked pebbles and cobbles of dolostone and phosphate from the underlying Arcadia Formation are common in the base of the shell bed sequence. The shell beds consist primarily of well preserved mollusc shells in an unconsolidated matrix of fine quartz sand. In Leisey Shell Pit 1 there are two major superposed shell beds separated by an erosional unconformity, and locally by a thin layer of indurated freshwater limestone. These two units are informally designated the lower and upper shell beds, respectively (Fig. 3). The upper and lower shell beds are similar lithologically, but differ in the composition of their molluscan faunas (Portell et al. 1992) and by the presence of dark organic-rich silt and clay lenses in the lower shell bed. The size, stratigraphic position, and faunal composition of these lenses varies throughout the Leisey pits. All of the major vertebrate concentrations 24 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 37, PT. I, NO. 1 (Leisey lA, 18, 34 and 38) originate from these organic lenses. One common type of organic unit encountered in the Leisey pits is composed of a mixture of dark organic clay and silt, fine to medium-grained sand, well preserved freshwater mollusc shells (e.g. the gastropods Fiviparus and P/anorbeUa and unionid bivalves), and locally abundant fossil wood. Other organic lenses consist primarily of shells of the estuarine bivalves Rangia or Crassostrea. The most extensive of these organic units, Leisey 3B, is not actually a lens but consists of a layer of very dark-colored clay and silty clay from 20 cm to over 1 m in thickness occurring widely throughout Leisey Pit 3. Vertebrate fossils are sometimes locally abundant in Leisey 3B, but were never concentrated to the extent seen in the two main "bone beds" (Leisey lA and 3A). Leisey 14 the largest and most thoroughly studied organic unit in the lower shell bed, occurs higher in the section than most of these lenses (approximately 4.5 m above the top of the Arcadia Formation, Fig. 3), and differs from them in containing predominantly marine molluscs. Leisey lA varies in thickness from 5 to 30 cm over an area of about 2000 mt It consists of an unconsolidated, poorly sorted mixture of well preserved mollusc shells, vertebrate bones and teeth, fossilized mangrove root casts, fine-grained quartz sand, silt, and dark brown mud. The deposit thins gradually towards its margins, with vertebrate remains becoming increasingly scarce. Leisey lA is often referred to as a "bone bed" because of the tens of thousands of vertebrate fossils it contained, although volumetrically, marine mollusc shells comprised most of the deposit. The taxonomic composition of the Leisey 1 A marine molluscs is generally similar to that of the main lower shell bed (Portell et al. 1992). The freshwater molluscs of Leisey 14 in contrast to those found in the lower organic lenses, often show signs of transport damage. The mangrove roots probably were not contemporaneous with the deposition of the Leisey lA shells and vertebrate fossils, but more likely grew down through the sediments at a later date. This explains the absence of mangrove pollen in the Leisey lA sediments (Rich and Newsom this volume). Immediately above the Leisey lA bone bed, and separated from it by a poorly defined unconformity, is a 30 to 50 cm thick layer of fossiliferous, indurated, calcareous freshwater limestone. This layer extends beyond the boundaries of Leisey 14 locally separating the lower and upper shell beds. The limestone contains great numbers of freshwater gastropod shells (especially Planorbella scalaris), some poorly preserved and apparently reworked marine mollusc shells, fine-grained quartz sand, and rare bones. The vertebrate fossils pertain almost exclusively to freshwater tan such as emydid and trionychid turtles, alligators, and water birds. The fauna suggests a freshwater origin for the limestone. Such freshwater "maris" are commonly interbedded with marine strata in the Plio- Pleistocene stratigraphic sequence in southern Florida (e.g. DuBar 1958, 1962). An erosional unconformity above the indurated calcareous mari separates it from the upper marine shell bed. Reworked fragments of the marl are present in MORGAN & HUIBERT: OVERVIEW OF THE LEISEY SHELL Prr LOCAL FAUNA 25 the base of the upper shell bed. Like the lower shell bed and bone bed, the upper shell bed lacks distinct bedding and is composed predominantly of marine mollusc shells. However, in contrast to the bone bed, the upper shell bed has few freshwater gastropods, is nearly devoid of bones, lacks fossilized mangrove roots, and has a higher percentage of fine-grained sand and a lower percentage of silt and clay. The only notable vertebrate fossils from the upper shell bed in the Leisey 1 pit are a partial plastron of the loggerhead sea turtle, Caretta, and a tooth and vertebra of Bison. Overlying the upper shell bed is a 2.4 m thick layer of massive unconsolidated Quaternary quartz sand containing no fossils. Leisey lB is a small vertebrate site located several hundred meters south of Leisey lA and about 3 m lower in the stratigraphic section. The bones occurred in a thin lens at the base of the lower shell bed not far above the contact with the underlying Arcadia Formation. Some of the vertebrate fossils were collected from a rubble zone lying directly on top of the eroded surface of the Arcadia Formation. Based on the limited vertebrate assemblage present, the fauna from Leisey lB is very similar to that of Leisey lA. The most diagnostic mammals present in Leisey 1B are the glyptodont Glyptotherium arizonae, the giant armadillo Holmesina «floridanus, the giant tapir Tapirus hoysii, and the primitive mammoth Mammuthus hayi, all indicative of a late early Irvingtonian (early Pleistocene) age. Leisey 3A occupied about one fourth the area of Leisey lA. It too is located stratigraphically high within the lower shell bed (Fig. 3). It differs from Leisey lA in containing a very limited large terrestrial vertebrate fauna overwhelmingly dominated by juvenile individuals of the 11ama, Hemiauchenia macrocephala, many ofwhich consist of associated skeletons. Leisey 3A has a considerably richer and more diverse terrestrial and freshwater microvertebrate fauna than Leisey lA. The most common tan in the molluscan fauna are the brackish water bivalve Rangia and the freshwater gastropod Fiviparus. No indurated freshwater mart layer separates Leisey 3A from the overlying shell bed, nor are mangrove roots present as in Leisey lA. Regional Stratigraphic Correlation.-The Pliocene and Pleistocene stratigraphy of southern Florida is currently undergoing intensive study by a large number of geologists and paleontologists (e.g. Lyons 1991; DuBar et al. 1991; Scott and Allmon [eds.] 1992). Clearly, there will be many changes in the nomenclature of the geologic units recognized in this region (e. g. Waldrop and Wilson 1990; DuBar at al. 1991; Scott 1992). It is not our intention here to revise the stratigraphic nomenclature of South Florida since we are not stratigraphers, nor do we study molluscs, the primary fossil group upon which the southern Florida biostratigraphic sequence is based. Our goal is to place the stratigraphic section exposed in the Leisey Shell Pit into the currently recognized stratigraphic framework for the region to insure that our work will be comprehensible to present and future workers. Lyons (1991) has recently summarized the biostratigraphic 26 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 37, PT. I, NO. 1 basis for recognizing the various formational units withing the Plio-Pleistocene shell beds in southern Florida. We follow his subdivision and characterization of these geologic units. A century of geologic and paleontologic investigation has resulted in a generally agreed upon stratigraphic sequence for the extensive Pliocene and Pleistocene shell beds of southern Florida (e.g. DuBar 1974; Lyons 1991), although see Scott (1992) for an alternative view. On the basis of stratigraphic superposition there is little disagreement that the relative ages of the units in question are (from oldest to youngest): Pinecrest Beds (also known as the Pinecrest Sand Member of the Tamiami Formation of Hunter 1968; the Fruitville Formation of Waldrop and Wilson 1990; and the Myakka Member of the Sarasota Formation of DuBar et al. 1991), Caloosahatchee Formation Bermont Formation, Fort Thompson Formation, and Coffee Mill Hammock Formation (Fig. 2). These strata are often similar in their lithological composition, generally consisting of abundant shells of marine molluscs in a matrix of unconsolidated fine quartz sand, but also including beds of calcareous marl, indurated freshwater limestone, and dark organic-rich silts and clays. These lithologies reflect a diversity of nearshore marine, estuarine, and freshwater depositional environments. The southern Florida formations composed predominantly of marine shell beds are primarily differentiated on the basis of the composition of their molluscan faunas. As suggested by many previous workers, these formations are perhaps more properly regarded as biostratigraphic units (biozones) because the North American Stratigraphic Code (1983) requires that formal lithostratigraphic units be differentiated on the basis of lithology, not fossil content. In the absence of a formally proposed, well documented biostratigraphic nomenclature for Plio- Pleistocene units in southern Florida, such as that proposed for the middle Atlantic Coastal Plain by Blackwelder (198la), we continue to follow current geological usage in discussing these units (e. g. Lyons 1991). The presence of stratigraphically restricted species of molluscs has until recently been the primary method used to correlate geologic units in southern Florida. The percentage of extinct species of molluscs in a fauna termed the "Lyellian percentage," is another method that has been used to determine relative age among Florida shell beds. Portell et al. (1992, this volume) identified more than 200 species of molluscs from the lower shell bed and bone bed from Leisey Shell Pit 1, approximately 3% of which are extinct. Previously published estimates of 10-12% extinct species of molluscs from Leisey (Hulbert and Morgan 1989; Webb et al. 1989) were based upon a preliminary analysis of the molluscan fauna and are now known to be too high. The Lyellian percentage of extinct species of molluscs from Leisey is intermediate between faunas of the Bermont and Ft. Thompson formations (DuBar 1974; Lyons 1991). Bermont molluscan faunas typically contain from 10-20% extinct species (Hoerle 1970; DuBar 1974; Stanley 1986), compared to those from the younger Fort Thompson Formation which are MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 27 composed of fewer than 5% extinct taxa. The Caloosahatchee Formation, which directly underlies the Bermont Formation contains from 50 to 65% extinct species of molluscs (Olsson and Harbisson 1953; Stanley 1986; Lyons 1991). DuBar (1958) suggested that the Caloosahatchee Formation was late Pleistocene in age based primarily on evidence from vertebrate fossils. He later regarded the Caloosahatchee to be early and middle Pleistocene (1974), whereas DuBar et al. (1991) placed the Caloosahatchee in the early Pleistocene. We have re-examined the small sample of mammalian fossils (Holmesina, Eremotherium, advanced Equus, and Palaeolama) reported from the Caloosahatchee Formation by DuBar (1958; 1974). These taxa indicate a latest Pliocene or Pleistocene age (i.e. Irvingtonian or Rancholabrean) but, with the possible exception of the Ho/mesina, are not sufficiently diagnostic to provide a more specific indication of the age. The size of several Holmesina osteoderms collected by DuBar from the Caloosahatchee Formation is suggestive of a latest Pliocene or early Pleistocene (early Irvinglonian) age. Within the past five years, an extensive vertebrate fauna has been collected from the Caloosahatchee Formation in the De Soto Shell Pit in De Soto County. Preliminary analysis of the De Soto Shell Pit vertebrate fauna (see discussion below and Table 2) suggests correlation with the well known latest Pliocene (earliest Inangtonian) Inglis lA LF of northern Florida. Lyons (1991) also considered the Caloosahatchee Formation to be very late Pliocene in age on the basis of its molluscan fauna. DuBar (1974) originally proposed the Bermont Formation as an informal unit, but distinguished the Bermont Formation from the underlying Caloosahatchee Formation primarily by the absence of most typical Caloosahatchee molluscs, and by the presence of a few species that are restricted to the Bermont. DuBar (1974) specifically noted that these two units were similar lithologically. Among the species of molluscs unique to the Bermont formation (McGinty 1970; DuBar 1974; Lyons 1991), only the gastropod Strombus moyacensis has been identified from Leisey (Portell et al. 1992). The lower shell bed at Leisey (including vertebrate sites Leisey lA and 3A) is tentatively referred to the Bermont Formation on the basis of compatible lithology, faunal similarity, and the presence of seven extinct invertebrate taxa (see Portell et al. this volume). In his original description of the Bermont Formation, DuBar (1974) noted that it was found in widely scattered exposures from Charlotte County north to Levy County along the West Coast, and in the vicinity of Lake Okeechobee on the Atlantic Coast. The best known Bermont molluscan faunas occur 100 km or more south of Leisey in Charlotte, Gl*les, Hendry, and Palm Beach counties. The Belle Glade Rock Pit in Palm Beach County (Hoerle 1970; McGinty 1970), perhaps the best known Bermont locality, contains over twice the number of molluscan species as Leisey of which approximately 15% are extinct (Hoerle 1970; Lyons 1991). However, the fossils from the Belle Glade Rock Pit were collected entirely from spoil piles, and thus may contain a mixture of faunas (Lyons 1991). The vast 28 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 37, PT. I, NO. 1 majority of the Leisey molluscs were collected from in-place stratigraphic sections. The reduced number of extinct species at Leisey suggests that its molluscan fauna may be somewhat younger than other Bermont faunas, and as such is intermediate in age between this unit and faunas of the Fort Thompson Formation. Geochronology of the Leisey Shell Pit Beds.-In this section we review previous attempts to date the Bermont and Fort Thompson formations, and briefly summarize paleomagnetic (see MacFadden this volume) and stable strontium isotope (see Jones et al this volume) data from Leisey. The Leisey Shell Pit provides an important cross-reference point for biochronologies based on marine molluscan assemblages (e.g., Blackwelder 198la) and terrestrial mammals (North American Land Mammal Ages, e.g., Savage and Russell 1983; Woodburne 1987). Biostratigraphic data from various microfossil groups present in the Leisey strata (e.g., foraminifera, ostacodes, calcareous nannoplankton) have not yet been analyzed. Prior to the 19605, beds now referred to the Bermont Formation were usually considered the uppermost strata of the Caloosahatchee Formation (DuBar 1958; 1962). The Bermont Formation was proposed as an informal name in its original description (DuBar 1974), but has received widespread use in subsequent publications (e. g. Lyons 1991; DuBar et al. 1991) and was listed as a vaiid unit in Swanson et al. (1981). Strata placed in the Bermont Formation by DuBar (1974) have variously been referred to as Unit F (DuBar 1962), Unit A (OIsson 1964), Glades Unit (Hoerle 1970; McGinty 1970), the Belle Glade Member of the Fort Thompson Formation (Hunter 1968), and the Okeechobee Formation (Scott 1992). There are two prevailing opinions among invertebrate paleontologists regarding the age of the Bermont Formation. DuBar (1974), Petuch (1988), and DuBar et al. (1991) considered the Bermont to be middle Pleistocene, falling between 0.6 and 0.3 Ma. Although Blackwelder (198lb) placed the Bermont in the late Pleistocene, he did not recognize a three-part subdivision of the Pleistocene. His proposed age of approximately 0,54.4 Ma for the Bermont Formation would place this unit in the middle Pleistocene as recognized here. Evidence for a middle Pleistocene age comes primarily from the results of amino acid racemization studies (Mitterer 1975), from the stratigraphic position of the Bermont between the supposedly early Pleistocene Caloosahatchee and late Pleistocene Fort Thompson (DuBar et al. 1991), and indirectly through correlation with the Canepatch Formation (Oaks and Dubar 1974; Blackwelder 19814b; DuBar et al. 1991). Other invertebrate pateontologists (e. g. Hoerle 1970) have regarded the Bermont as either late Pliocene or early Pleistocene, citing little evidence beyond the Lyellian percentage of 10 to 25% extinct species of molluscs. Bender (1973) obtained dates ranging from 1.9-1.75 Ma for the Caloosahatchee Formation using the He/U method on corals, which, if accurate, would constrain the overlying Bermont Formation as younger than 1.7 Ma. MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 29 Oaks and DuBar (1974) correlated the Bermont Formation with the Canepatch Formation of North and South Carolina. The Canepatch is a relatively securely dated deposit assigned a middle Pleistocene age on the basis of a uranium-series date of 460* 100 ka (Szabo 1985), normal geomagnetic polarity, and ostracode biochronology (Cronin 1980). Blackwelder (19814b) placed the age of the rinepatch Formation between 0.5 and 0.4 Ma assigning it to the Myrtlean Substage of the Longian Stage. Longian Stage molluscan assemblages contain an essentially modern fauna with less than 5% extinct species. Blackwelder (198la), citing Oaks and DuBars (1974) correlation of the Canepatch and Bermont, also placed the Bermont in his Myrtlean Substage. Despite these previous age estimates, several lines of evidence indicate that the Bermont is substantially older than the Canepatch. Geochronological data derived from magnetic polarity, strontium isotope stratigraphy, sea level, and vertebrate chronology are very useful in helping to determine the age of the Bermont Formation at the Leisey Shell Pit. Samples for pateomagnetic study were taken through aSm section at Leisey, including samples bracketing the vertebrate-bearing lenses Leisey 14 34 and 38. All sediments from both the Leisey lA and Leisey 3A sites are of reversed magnetic polarity and lie within the Matuyama Chron (Webb et al. 1989; MacFadden this volume). The boundary between the Matuyama Chron of generally reversed polarity and the Brunhes Chron of normal polarity is 0.78 Ma (Cande and Kent 1992; Valet and Meynadier 1993). The Canepatch Formation of the Carolinas is geomagnetically normal (Cronin 1980), and thus is not synchronous with the reversed sediments from Leisey. Leisey could correlate with the latest Matuyama, between 0.99 and 0.78 Ma but other evidence argues against this hypothesis. Most of the uppermost zone of the Matuyama Chron corresponds with two periods of continental glaciation (glaciations F and G of Richmond and Fullerton 1986). However, the two Leisey sites were deposited very close to current sea level and thus would not correlate with a glacial interval characterized by signficantly lowered sea levels. Furthermore, the marine molluscan fauna from Leisey does not contain evidence of cooler water forms (Portell et al. 1992). The interval between 1.55 and 1.0 Ma was a warm period lacking major glacial episodes (Richmond and Fullerton 1986). Ratios of stable strontium isotopes from biogenic carbonate (shells of the marine bivalve Chione cancellata) from the Bermont Formation at Leisey correspond to ages of 2.08 Ma forLeisey lA and 1.33 Ma for Leisey 3A (Jones etal this volume). When the 95% confidence intervals for the Leisey strontium isotope values (*0.56 Ma) are taken into consideration, Leisey lA could be as young as 1.52 Ma and Leisey 3A could be as old as 1.89 Ma yielding a possible overlap of almost 0.4 Ma between the two sites. Vertebrate biochronology, as discussed in detail below, favors a late early Irvingtonian age (1.6-1.0 Ma) for the Bermont at Leisey. 30 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 37, rr. I, NO. 1 In summary, both mammalian biochronology and geochronological data indicate that the Leisey Shell Pit LF is early Pleistocene in age, about 1.6 to 1.0 Ma. Faunal criteria strongly suggest that Leisey is younger than latest Pliocene la,mm such as Inglis lA and De Soto Shell Pit (i.e., younger than 1.6 Ma) and older than the late middle Irvingtonian McLeod Limerock Mine LF (older than 0.7 Ma). Biochronological data restrict the age of Leisey to the latter half of the early Irvingtonian or the first half of the middle Irvingtonian. Of these two possiblities the mammalian fauna is more suggestive of an early Irvingtonian age. Geochronological data also rule out an early middle Irvingtonian age (between 1.07 and 0.78 Ma). The similarity of Leisey to certain middle Irvingtonian vertebrate faunas suggests that Leisey falls late in the early Irvingtonian, and accordingly may be no more than several hundred tholl-£And years older than Cumberland Cave, Port Kennedy Cave, Hamilton Cave, and other early middle Irvingtonian faunas. The best estimate for the age of the Bermont Formation at the Leisey Shell Pit, taking into account all chronologic indicators, is between 1.55 and 1.1 Ma. Moreover. it is most likely that the Leisey lA and 3A vertebrate sites are less than 1.3 Ma. In contrast to the Bermont Formation, there has been relatively little disagreement concerning the age of the Fort Thompson Formation. Most evidence points to a middle or late Pleistocene age. In particular, the Coffee Mill Hammock Member of the Fort Thompson Formation or Coffee Mill Hammock Formation of some authors is rather securely correlated with the last major interglacial (Sangamonian) between 130-120 ka (DuBar 1974; Mitterer 1975; Lyons 1991). This was the last time sea level rose substantially higher than present levels (Bloom 1983). DuBar (1958:135) listed 13 vertebrate tan collected in situ in the Fort Thompson Formation. Contrary to his claims, none of these taxa are strictly limited to the late Pleistocene (Rancholabrean) as currently understood (Kurt6n and Anderson 1980; Lundelius et al 1987; Repenning 1987). A late Irvingtonian age is also possible on faunal grounds alone. Several specimens of Bison were collected in situ from the upper shell bed at Leisey Pit 1, which has been referred to the Fort Thompson Formation based on the lack of extinct species in the molluscan fauna. The occurrence of Bison essentially defines the Rancholabrean Land Mammal Age (Lundelius et al. 1987). Hohnesina septentrionalis, Sigmodon hispidus, and Tapirus veroensis all were collected from spoil in Leisey Pit 2, but are presumed to have been derived from the upper shell bed, as they were not recovered from the lower shell bed at Leisey despite intensive sampling. Among these three species, Sigmodon hispidus is characteristic of late Rancholabrean faunas in Florida whereas the latter two species occur in both late In@gtonian and Rancholabrean faunas (<0.6 Ma). However, the overlapping range zone for these three species plus Bison, occurs only during the Rancholabrean (0.3-0.12 Ma). Vertebrate fossils from Leisey support previous determinations that at least the upper units of the Fort Thompson Formation are MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 31 late middleor late Pleistocene in age. There is a significant gap, corresponding to most of the middle Pleistocene, between our proposed upper limit for the Bermont beds at the Leisey Shell Pit of about 1.0 Ma and strata of the Fort Thompson Formation containing Bison that are 0.3 Ma or younger. There are presently no middle or late Imingtonian vertebrate faunas known from Florida that occur in stratigraphic superposition with marine geologic units. VERTEBRATE BIOCHRONOLOGY OF THE LEISEY SHELL PIT LOCAL FAUNA Plio-Pleistocene vertebrate biochronology in Florida.-Table 2 shows the chronological distribution of 128 species of mammals in Florida during the late Pliocene and Pleistocene. Five Blancan and 11 Irvingtonian vertebrate faunas are listed separately in Table 2, whereas the early and late Rancholabrean are presented as composite faunas derived from a number of different sites. This table does not include all of the Blancan and Irvingtonian sites known from Florida only those with the largest and most chronologically significant faunas, arbitrarily defined as faunas containing 10 or more species of mammals. Several other important Florida Blancan and Irvingtonian sites that contain age-diagnostic mammals are discussed in the text. We caution that Table 2 does not provide complete mammalian faunal lists for the individual sites, but includes only those species we consider to be biochronologically diagnostic in Florida. For example, Insectivorg Chiroptera (with the exception of Desmodus), and many species of Rodentia are not included in Table 2, although these groups are often common members of the faunas listed. We emphasize that the data presented here are based primarily on Florida faunas and therefore, in the case of certain taxa, may not have widespread applicability to other North American vertebrate faunas of similar age. Examples include the late Blancan arrival in Florida of the armadillos Dasypus and Holmesina and the giant ground sloth Eremotherium, all of South American origin. These three genera have not been reported elsewhere in North America prior to the Irvingtonian. Another Neotropical immigrant, the huge flightless bird Titanis walleri, is unknown outside of Florida, yet its chronological range is restricted to the late Blancan and earliest Irvingtonian, and it is thus an excellent biostratigraphic indicator within the state. Whenever possible we attempt to correlate Florida vertebrate faunas with faunas elsewhere in North America especially in instances where the non-Florida faunas have been radiometrically dated or can be correlated to the magnetic polarity time scale. 32 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 37. Fr. I. NO. 1 Table 2. Biochronological distribution of Blancan, Irvingtonian. and Rancholabrean mammals in Florida An "X" indicates a definite identification, "?" a possible identification, and "-" an absence. Ear- Late liest Blan- Irving- can tonian (2.5- (2.0- 2.0 Ma) 1.6 Ma) Santa Macas- Kis- De Fe phalt sini- Soto River Haile Shell mee Haile Inglis Shell 1 15A Pit River 7C lA Pit Didelphis virginiana - - - - - - - Da~pus bellus XXXXXXX Holmesina floridanus XXXXXXX Holmesina septentrionalis - - - - - 667*othenum arizonae X X X X X Glyptotheriumfloridanum - Pachyarmatherium letseyi X Glossotherium chapadmalense XXXX Paramylodon harlani Megalonyx jeffersonii - - - - I X I X I X I X tx Megatonyx leptostomus X X X X Megalonyx wheatleyi Eremotherium mirabile - - I X t x Eremotherium n. sp. ? X Nothrotheriops texanus Desmodus archaeodaptes Desmodus stocki X I X I Borophagus diversi(lens Canis armbrusteri Canis dints - Cania edwardii X Canis latrans - Canis lepophagus Urocyon cinereoargenteus Urocyon minicephalus - XUrocyon n. sp. Procyon lotor - - - Procyon n. sp. ? ? 7 XX Arctodus pristinus X - X X Tremarctoilloridanus Conepatus leuconotus Conepatus robustus MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 33 Table 2 Extended. L.ate Early Late Early Middle Late Ranch- Ranch- Irving- Irving- Irving- ola- ola- tonian tonian tonian breanl brean2 Recent (1.6- (1.0- (0.6- (0.3Ma- (130- 1.0 Ma) 0.6 Ma) 0.3 Ma) 130 ka) 10 ka) Lei- Rig- sey Payne C,ys- by Cole- Haile Shell Pool Creek tai Shell Haile Mc- man 16A Pit Branch Mine River Pit 21 A I.£od 2A --------XX X XX-X-XXXXXX- X IX IX I X I X i X XXXXX -- X X t x I 1 X X tx I X i X I X I - X X I X I X 1 X X tx I x 1 1 1 I X t x > < X X X i X i X ix t X l l x l X IX I X X X?XX ? X- I IX I X I - X X - XXX- - - - X X X X ?X - -XXX X - - - - - X X X X -X-X - - XX XXX-XX- - - X - X X X~ - 34 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 37, PT. I, NO. 1 Table 2 Continued. Ear- L,ate licst Blan- Irving- can tonian (2.5- (2.0- 2.0 Ma) 1.6 Ma) Santa Macas- Kis- De Fe phalt sin) Soto River Haile Shell mee Haile Inglis Shell 1 15A Pit River 7C 1 A Pit Spilogale putorius - Spilogate sp. X Lutra canadensis - Satherium piscinarium X X Trigonictis cookii - -1 IX 'X x Trigonictis macrodon X - XX Callophoca obscura X X - Monachus tropicalis . X Dinobastis serus Felis amnicola - - Homotherium n. sp. ? ? Lynx rufus - Lynx sp. - X Miracinonyx inexpectatus X Miracinonyx cf. M. trumani Panthera atrox Panthera onca Puma concolor Smilodon fatalis - - - Smilodon gracilis X X X Chasmaporthetes ossifragus X - X l i x Castor canadensis X Castoroides leiseyorum Castoroides ohioensis Geomys pinetis - - - - Geomys propinetis XX XX Thomomys orientalis Zapus sp. Erethizon dorsatum - Erethizon kleini - X Erethizon sp. - X - Hydrochaeris holmesi X -- X Neochoerus dichroplax X X Neochoems pinckneyi MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 35 Table 2 Extended/Continued. Late Early Late Early Middle Late Ranch- Ranch Irving- Irving- Irving- ola- ola- tonian tonian tonian brean brean Recent (1.6- (1.0- (0.6- (0.3Ma- (130- 1.0 Ma) 0.6 Ma) 0.3 Ma) 130 ka) 10 ka) Ini- Rig- sey Payne Crys- by Cole- Haile Shell Pool Creek tai Shell Haile Me- man 16A Pit Branch Mine River Pit 2 1 A Leod 2A X X X X X X X X X X X 0 1 X X X IX X X 1 X 1 X X I X I I -- - X - - - X X X X X ---X X X XXX3 - X X - - - - X X X X X X - - - XX X ? - - - - - - - X X - -X X X XXXX X --- - XXX X - - - - - X X X X X X3 - X X X - X X 36 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 37, PT. 1, NO. 1 Table 2 Continued. Ear- Late liest Blan- Irving- can tonian (2.5- (2.0- 2.0 Ma) 1.6 Ma) Santa Macas- Kis- De Fe phalt sim- Soto River Haile Shell mee Haile Inglis Shell 1 15A Pit River 7C 1 A Pit Neochoerus sp. Neotoma floridana - - Neotoma sp. XX Orpomys palustris - Peromyscus large sp. ? Podomys floridanus Podomys n. sr Sigmodon bakeri - - Sigmodon curtin XX Sigmodon hispidus Sigmodon libitinua - - Sigmodon medius X X - Sigmodon minor X Atopomys salvelinus X Microt:43 penniylvanicus Neojiber alleni Neojiber leonardi Ondatra annectens - - Ondatra idahoensia X X Ondatra zibethicus Pitymys aratai Pitymys hibbardi Pitymys pinetorum Pedomys & sp. Synaptomys australis Synaptomys n. sp. Lepus 4 L. townsendii - Lepus sp X Sylvilagus floridanus Sylvilagus palustris - - - - - - - Sylvilagus webbi - 7 X ? ? X X Mylohyus floridanus XXX ---- Mylohyus fossilis - - - Platygonus bicalcaratus X X X MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 37 Table 2 Extended/Continued. L.ate Early Late Early Middle Late Ranch- Ranch- Irving- Irving- Irving- Ola- ola- tonian tonian tonian brean brean Recent (1.6- (1.0- (0.6- (0.3Ma- (130- 1.0 Ma) 0.6 Ma) 0.3 Ma) 130 ka) 10 ka) Lki- Rig- sey Payne Crys- by Cole- Haile Shell Pool Creek tai Shell Haile Mc- man 16A Pit Branch Mine River Pit 21 A I.,eod 2 A X --- X X X - - - X X X X X - - - - XXXX X I X I X I X - - - XXX - X X X X i 1 1 - 1 1 X X X X X - --XX -XXXX - - X X X - - X X3 X- X-- --- XX XX X -- -- XX XX X - - - - X -XX-- X X X-XXX - X XX X - - ?XX XXX 38 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 37, PT. I, NO. 1 Table 2 Continued. Ear- I-ate liest Blan- Irving- can tonian (2.5- (2.0- 2.0 Ma) 1.6 Ma) Santa Macas- Kis- De Fe phalt sim- Soto River Haile Shell mee Haile Inglis Shell 1 15A Pit River 7C 1 A Pit Platygonus compressus Platygonus cumberlandensis Platygonus vetus - - Hemiauchenia blancoensis X - X Hemiauchenia macrocephala X X Hemiauchenia n. sp. X Pakieolama mirijica - Capromeryx arizonensis X - - - X 1 & 1 X X - Odocoileus virginianus XXX X X ix lx x 1 x x tx ix Bison antiquus Bison latifrona - Bovidae, gen. indet. 5 X Tapirus haysii Tapirus veroensis - - - Tapirus n. sp. ?-?X X Cormohipparion emsliei XX - X x I q I Nannippus peninsulatus XXX Equus (Dolichohippus) sp. XXX Equus 7~aternus" Equus "leidyi" X X Equus (Hemionus) n. sp. Equus alaskae woup Equus laurentius soup - - Rhynchotherium praecursor X ~ - - - Cuvieronius tropicus XX - X Mammut americanum X X Mammuthus hayi Mammuthus columbi 1 The early Rancholabrean f~una is a composite list compiled from the fo[lowing sites: Bradenton, Daytona Beach, Haile 74 Haile BA Qldsmar, Williston 34 and Willfiton 38. . .. Arredondo 24 Cutler Hammock Devils DenIne lchetucknee River, Metbourne. Monkey Jungle Hamrnock. Reddick 1, ScmbioiJ Field, and Vero MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 39 Table 2 Extended/Continued. Late Early Late Early Middle Late Ranch- Ranch- Irving- Irving- Irving- 0]a- ola- tonian tonian tonian brean brean Recent (1.6- (1.0- (0.6- (0.3Ma- (130- 1.0 Ma) 0.6 Ma) 0.3 Ma) 130 ka) 10 ka) Lei- Rig- sey Payne Crys- by Cole- Haile Shell Pool Creek tal Shell Haile Mc- man 16A Pit Branch Mine River Pit 21A I.£od 2A - X X - - - - X X ? X X X - X x x t X X I 1 1 1 - XXXXX X X XX X XX XX IX t x l tx - XXXXXXXXXXX -X- X XXXXX XX XX X XX XX XXXXX X x t X I I t - - - XX XX XXXX X- - XX X - - - ? X X 34 NO longer found in Florida, but stll sulvives elsewhere in North America The Caribbean monk seal has gone extinct within the past 40 years. 5 J. McDonald (pm. comm.) thinks this taxon may be related to Old Wold Pliocene Bi,on 40 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 37, PT. I, NO. 1 A quote from Lundelius et al. (1987:218) is particularly appropriate to the difficulties encountered when tfying to correlate Florida Pliocene and Pleistocene faunas: "Latitudinal, regional, and ecological factors lead to faunal provincialism that together with lack of radiometric and paleomagnetic control makes correlation of faunas difficult." Because most Florida Blancan and Irvingtonian vertebrate faunas lack radiometric and paleomagnetic control, we must rely almost entirely on biochronologic comparisons with well-dated faunas from the western United States. However, these correlations may be limited by the faunal provincialism noted by Lundelius et al. (1987). For instance in eastern North America the late Blancan and early Irvingtonian (2.5 to 1.0 Ma) are represented almost exclusively by vertebrate faunas from Florida, many of which appear to sample a more tropical fauna than typical western faunas of this time period. Despite certain peculiarities in Florida Blancan and Irvingtonian faunas, there are still more similarities than differences between Florida and western faunas of this age, and these faunal similarities will be stressed throughout this paper. Data on sea level are helpful in placing certain Florida vertebrate faunas in the context of glacial and interglacial stages. There are two general circumstances in which information derived from vertebrate fossil sites can provide some indication of sea level. Low sea level faunas, presumably deposited during glacial intervals, are indicated by sites collected below present sea level that contain no evidence of marine vertebrates. By these criteria, the late Blancan St. Petersburg Times LF and the early Irvingtonian Inglis lA and Crystal River Power Plant local faunas are examples of low sea level faunas. High sea level faunas, presumably reflecting interglacial conditions, are indicated by sites collected well above modern sea level that contain marine vertebrates. Examples of high sea level faunas are the late Blancan Haile 15A and Kissimmee River sites, the early Irvingtonian De Soto Shell Pit, and the early Rancholabrean Daytona Beach and Oldsmar local faunas. The number of glacial and interglacial intervals, and hence the number of eustatic sea level changes throughout the late Pliocene and Pleistocene, appears to be much greater (Shackleton and Opdyke 1977) than the four glaciations (Nebraskan, Kansan, Illinoian, and Wisconsinan) traditionally recognized during the Pleistocene. We use the relative sea level position of several Florida vertebrate fossil sites, in conjunction with other geochronological data, to help determine the placement of the site relative to the worldwide sea level curve (e.g. Haq et al. 1987). No Florida pre-Rancholabrean vertebrate faunas have been radioisotopically dated, although attempts are underway to obtain uranium-series dates on corals collected from nearshore marine shell beds in association with vertebrate faunas. However, uranium-series dates are not reliable for sites older than about one million years (Szabo 1985). Bender (1973) determined helium/uranium ages on samples of corals from several Florida Pliocene and Pleistocene marine geologic units, including the Pinecrest Beds and Caloosahatchee Formation. This dating MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 41 technique has not been applied recently, nor has it been used to directly date any vertebrate faunas. Other methods of radioisotopic dating (K/Ar, Ar/Ar, etc.) are not applicable in Florida sites because the surficial geology of this region is devoid of basalt flows, volcanic ash beds, or other igneous rocks containing minerals normally used for dating vertebrate-bearing beds in the western United States and elsewhere. Long stratigraphic sequences with a paleomagnetic polarity reversal chronology are unknown from the Florida Plio-Pleistocene. However, paleomagnetic signatures (i.e. normal or reversed) have now been obtained from two Florida vertebrate faunas, including Leisey (Webb et al. 1989; MacFadden this volume) and the late Blancan Macasphalt (=APAC) Shell Pit (Jones et at 1991). Most Blancan and Irvingtonian karst deposits in northern Florida (e.g. Haile 154 Haile 164 McLeod, Coleman 2A) were destroyed by mining operations many years ago, and thus are no longer available for paleomagnetic sampling. In the future, we intend to obtain a paleomagnetic signature for all Florida Blancan and Irvingtonian sites containing sediments suitable to this type of analysis. An integrated approach has been used to determine the age of the vertebrate- bearing deposits at the Leisey Shell Pit, applying data from paleomagnetic polarity stratigraphy, strontium isotope chronology, relative sea level position, and mammalian and molluscan biochronology (see Jones 1992). Many Florida Plio- Pleistocene vertebrate sites, particularly deposits in the northern portion of the peninsula, do not lend themselves to this type of integrated analysis. The majority of northern Florida Blancan and Irvingtonian sites are composed of terrestrial or freshwater sediments that occur as isolated cave, sinkhole, or fissure fillings in Eocene marine limestones, and cannot be correlated to a regional stratigraphic sequence. Most also lack associated marine vertebrate and invertebrate faunas, thus eliminating the possibility of strontium isotope analysis, determination of relative sea level position, or comparison with marine molluscan biochronology. Therefore, sites such as the Leisey Shell Pit are extremely important cross- references that allow us to compare terrestrial and marine biochronologies, and to contrast these results with data obtained from other geochronological techniques. Biochronology of the Leisey Mammalian Fauna.-The Leisey Shell Pit Local Fauna has one of the richest samples of large terrestrial mammals known from any Imingtonian site in North America. Among the 49 mammalian tan listed in Table 1, 33 are large mammals. Large herbivores numerically dominate the Leisey lA mammalian fauna, in particular the 11amas Palaeolama mirifica and Hemiauchenia macrocephola, two species of the horse Equus, the ground sloths Paramylodon harlani and Nothrotheriops texanus, Be peccary Platygonus vetus, and the mammoth Mammuthus hayi. The most common large carnivore is the sabercat Smilodon graci/is. The small mammal fauna consists of one species of shrew, two lagomorphs, and nine rodents. Five marine mammals have been 42 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 37, Fr. I, NO. 1 identified from Leisey, including three odontocete cetaceans, the manatee Trichechus, and the seal Monachus. The age of the Leisey Shell Pit LF has been determined principally from its land mammal fauna. However, the biochronologic significance of selected non- mammalian taxa from Leisey will also be discussed. The large and well preserved samples of carnivores, ungulates, and xenarthrans, and to a lesser extent rodents, from Leisey permit detailed taxonomic and biochronological comparisons of this fauna with well known Irvingtonian faunas from Florida and elsewhere in North America (e.g. Kurt6n and Anderson 1980; Lundelius et al. 1987; Repenning 1987). Preliminary biostratigraphic analyses of the Leisey Shell Pit vertebrate fauna have already been published (Hulbert and Morgan 1989; Webb et al. 1989). These studies and the present analysis indicate that the Leisey Shell Pit LF correlates to the later half of the early Irvingtonian between 1.6 and 1,0 Ma, and most likely to the later half of this interval. This age assignment is based on a number of mammalian taxa, including first appearances of immigrants from both South America and the Old World, overlapping range zones of certain indicator species, the evolutionary stage of taxa within certain well known lineages, and the absence of most taxa characteristic of either Blancan or middle Irvingtonian and younger faunas. In addition to age differences, there are many other reasons why taxa may be absent from a fauna including collecting bias, taphonomic or paleocological factors, and differences in biogeography. The faunal differences between the four individual sites comprising the Leisey Shell Pit LF are probably related to pateoecological factors. For instance, at Leisey lA Mammuthus is the dominant proboscidean and Nothrotheriops and Paramylodon are the only two ground sloths present, whereas the gomphothere Cuvieronius and the giant ground sloth Eremotherium are the most common members of these two groups in the Leisey Shell Pit 3 site. Other faunal anomalies between the Leisey sites, such as the presence of Glyptotherium arizonae only at the base of the lower shell bed in Leisey Pit 1, may reflect slight differences in age between the collecting localities. Xenarthra.--Like many other Florida Pliocene and Pleistocene sites, the Leisey Shell Pit LF has a diverse sample of xenarthrans, including three genera of armadillos, one genus of glyptodont, and four genera of ground sloths. Among Leisey xenarthrans, only the armadillo Dasypus bellus and the ground sloth Paramylodon harlani are considered conspecific with Rancholabrean species. D. bellus first appears in Florida during the late Blancan and persists throughout the remainder of the Pliocene and Pleistocene, going extinct at the end of the Rancholabrean. Although D. beUus is the only species of Dasypus recognized in North America during this time period, this armadillo shows a substantial size increase during its 2.5 million year history (Robertson 1976). The Leisey sample MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 43 of D. bellus is intermediate in size between small specimens from the late Blancan and the more typical large Rancholabrean form (Downing and White this volume). The taxonomic and evolutionary history of the giant armadillo or pampathere Hohnesina has been reviewed by Edmund (1985, 1987) and Hulbert and Morgan (1993). These studies documented significant evolutionary change in Holmesina from its first appearance in North America in the late Blancan until its extinction in the late Rancholabrean. Hulbert and Morgan (1993) referred the Leisey sample to the smaller of the two recognized species, H. floridanus, rather than to the much larger H. septentrionalis, which occurs in the middle Irvingtonian through Rancholabrean. They divided Florida Holmesina samples into four recognizable groups that are useful in a biochronologic context: 1) very small individuals of H. floridanus are known only in late Blancan sites, such as the type locality Haile 15A; 2) a slightly larger form referred to H.floridanus occurs in the latest Blancan Haile 7C LF; 3) an intermediate-sized form also referred to H. floridanus is known from the early Irvingtonian; and 4) the very large species H. septentrionalis ranges from the middle Irvingtonian through the Rancholabrean. Intermediate-sized specimens of H. floridanus, such as those found at Leisey, help restrict the age of this fauna to early Irvingtonian (2.0 to 1.0 Ma). The oldest record of Holmesina outside of Florida is from the early Irvingtonian Gilliland LF in Texas (Hibbard and Dalquest 1966), an approximate temporal equivalent of Leisey. One of the most intriguing members of the Leisey mammalian fauna is a new genus and species of large armadillo, Pachyarmatherium leiseyi, named and described by Downing and White (this volume). The presence of an undescribed shelled edentate from several Irvingtonian sites in southern Florida has been known for some time based on a small sample of osteoderms. This taxon had been confused with Dasypus bellus until the discovery of an extensive sample of small, but very thicki hexagonal osteoderms from the Leisey Shell Pit. Pachyarmatherium leiseyi also appears to be a useful biostratigraphic indicator within the state, as all records are either late Blancan or early Irvingtonian. The oldest known specimens of P. /eiseyi are from the late Blancan Kissimmee River 6 Site and the earliest Imingtonian Forsberg Shell Pit LF (late Pliocene). Late early Irvingtonian faunas such as Leisey and Payne Creek represent the youngest known occurrences of this species. Glyptotherium has a rather spotty distribution in Florida, both geographically and chronologically. It is one of the earliest Neotropical immigrants to participate in the Great American Interchange, where it is first recorded from late Blancan faunas in Arizona Texas, and peninsular Florida (Gillette and Ray 1981). Except for the Florida samples, Gillette and Ray (1981) referred all other North American Blancan glyptodonts to the small species G. texanum. They tentatively referred glyptodont osteoderms from the late Blancan Santa Fe River sites and the earliest In'ingtonian Inglis lA LF to G. arizonae. G. arizonae is a large, thick-shelled species reported from three early Irvingtonian faunas in the western United States: 44 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 37, PT. I, NO. 1 Curtis Ranch, Arizona (type locality); Holloman, Oklahoma; and Gilliland, Texas (Gillette and Ray 1981). Glyptodont fossils collected from late Blancan and early Irvingtonian sites in Florida (including Leisey) in the ten years since of the publication of Gillette and Ray's (1981) monograph all appear to be referable to G. arizonae as well. Glyptotherium is rare in the Leisey Shell Pit LF, and is absent from the two richest sites, Leisey lA and 3A. G. arizonae is represented at Leisey by a series of associated osteoderms collected from the base of the lower shell bed in Pit 1 in association with Mammuthus. Glyptotherium apparently was absent in Florida during the middle and late Irvingtonian. The smaller, thinner-shelled species, Glyptotherium floridanum, is restricted to Rancholabrean faunas in Florida (Gillette and Ray 1981). Four species of ground sloths have been identified from Leisey, an undescribed species of Eremotherium (De Iuliis and Cartelle in prep.), Megalonyx wheatleyi, Nothrotheriops texanus, and Paramylodon harlani 04€Donald \~s volume). The new species of Eremotherium is distinguished from the Rancholabrean species, E mirabile, by the presence of four well developed claws on the manus, as opposed to only two claws in the later species (Hulbert et at 1989). With the exception of the bones of digits 1 and 2 of the manus (metacarpals, phalanges, and claws), the remaining elements of the skeleton are very similar in the two species. The new species of Eremotherium has so far been confidently identified from the latest Blancan Haile 7C LF and the early Irvingtonian De Soto Shell Pit, Inglis lA, Haile 16A, Leisey Shell Pit, Crystal River Power Plant, and Payne Creek Mine local faunas. Other records of Eremotherium of similar age, but lacking the diagnostic skeletal elements of the manus, include the late Blancan Kissimmee River, Lehigh Acres, and Brighton Canal local faunas and the early Irvingtonian Pool Branch and Haile 21A local faunas. The Eremotherium remains from these five sites are tentatively referred to the new four-clawed form based on their similarity in age to confirmed records of this species. Eremotherium has been recorded from the base of the lower shell bed in Leisey Pit 1 and is fairly common in Leisey Pit 3, but is absent from Leisey lA and 3A. The largest Florida sample of E. mirabile is from the early Rancholabrean Daytona Beach LF (Edmund et al. in prep.). E mirabile was very rare in Florida during the late Rancholabrean. McI)onald (1977) reviewed the fossil history of Megalonyr in Florida. He identified a small, endemic Florida form of the typical Blancan species, Megalonyx leptostomus, from the late Blancan Santa Fe River 1 LF and the earliest Irvingtonian Inglis 1 A LF. Additional specimens of this dwarf M. leptostomus have now been identified from the late Blancan Macasphalt Shell Pit, Kissimmee River, St. Petersburg Times, and Haile 7C faunas and the earliest Irvingtonian De Soto Shell Pit LF. Megatonyx has only recently been recorded from the Leisey Shell Pit LF based on a nearly complete skull from Leisey 3B. This genus is absent from Leisey lA and 3A. The Leisey Megalonyx is distinctly larger than the MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 45 Florida material ofM. leptostomus and is here tentatively referred to M. wheatleyi. According to McDonald (1977), M. wheatteyi is intermediate in size between the smaller Blancan and earliest Irvingtonian M leptostomus and the larger late Pleistocene species M. jdersonii. Other Florida localities for M. wheat/eyi are the late early Irvingtonian Haile 16A, Payne Creek Mine, and Crystal River Power Plant local faunas and the middle Irvingtonian McLeod LF (Mci)onald 1977). M. wheatleyi appears to be restricted to the late early and middle Irvingtonian in Florida whereas the larger M. jel~ersonii does not appear until the Rancholabrean. Additional records of M. wheatleyi include early Iivingtonian faunas from Holloman, Oklahoma and Vallecito Creek, California and middle In'ingtonian faiinag from Port Kennedy Cave, Pennsylvania (type locality), Cumberland Cave, Maryland, and Cudahy, Kansas (McI)onald 1977). Nothrotheriops is unknown in North America prior to the early Irvingtonian, and thus is apparently one of the last genera of South American immigrants to participate in the Great American Interchange. Irvingtonian specimens of Nothrotheriops are now regarded as a separate species, N. texanus, distinguished by its smaller size and more slender cranium from the better known Rancholabrean species, N. shastensis (see Akersten and McDonald 1991; McDonald this volume). The oldest well-dated records of N. texanus are from the early Irvingtonian Vallecito Creek LF, California, Gilliland LF, Texas, El Golfo LF, Sonora, Mexico, and Leisey Shell Pit and Pool Branch of Florida (Hibbard and Dalquest 1966; McDonald 1985, this volume). The Nothrotheriops sample from Leisey lA is the largest Iningtonian sample of this genus in North America (McI)onald this volume). "Glossotherium" chapadmalense is one of the first South American immigrants to reach North America following the formation of the Panamanian isthmus. Although the systematic relationships remain unresolved, it appears that the younger species Paramylodon hariani was derived from "G." chapadmalense sometime during the late Blancan. These two species almost certainly belong in the same genus (McI)onald this volume). "G." chapadmalense is a small species represented by a partial skeleton from the late Blancan Haile 15A LF (Robertson 1976). Other late Blancan records of "G." chapadmalense include the Santa Fe 1, Macasphalt Shell Pit, and Kissimmee River local faunas from Florida (Table 2), as well as Mt. Blanco, Texas (Dalquest 1975) and 111 Ranch, Arizona (Galusha et al. 1984). The oldest Florida record of the larger species, P. harlani, is from the earliest Irvingtonian Inglis lA LF. P. harlani is found in Florida throughout the Irvingtonian and Rancholabrean. McDonald (this volume) demonstrates a gradual size increase in this species from the early Irvingtonian through the Rancholabrean. Carnivora.-Berta (this volume) identified two species of large canids from the Leisey Shell Pit LF, Canis edwardii and C armbrusteri. Both of these canids 46 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 37, PT. I, NO. 1 are restricted to North American Irvingtonian faunas. However, prior to the discovery of Leisey, C edwardii was known only from early Irvingtonian faunas, whereas C. annbrusteri was restricted to middle and late In@gtonian faunas. These two species are now known to co-occur in two late early Irvingtonian sites in Florida Leisey and Haile 21A. C edwardii also is known from five other Florida early Irvingtonian faunas, including the earliest Irvingtonian Inglis 14 De Soto Shell Pit and Forsberg Shell Pit local faunas and the late early Irvingtonian Crystal River Power Plant and Rigby Shell Pit local faunas. C annbrusteri has also been identified from the late middle Ilvingtonian McLeod Limerock Mine and the late Irvingtonian Coleman 2A LF (Martin 1974; Berta this volume). Florida records of C edwardii and C armbrusteri suggest that the overlapping range zone of these two species occurs only during a restricted interval of time in the late early Irvingtonian. The sample of the sabercat Smilodon gracilis from Leisey is the most complete known from any Irvingtonian site (Berta this volume). Although the Leisey specimens are referable to S. gracilis, Berta (1987; this volume) noted that certain evolutionary changes occurred within this species during the early and middle Irvingtonian. S. gracilis is also well represented by material from the earliest Irvingtonian Inglis lA LF and the middle Irvingtonian Port Kennedy Cave (type locality) and McLeod Limerock Mine local faunas (Berta 1987; this volume). The Leisey S. gracihs is intermediate in size and several morphological features between the samples from the older Inglis lA LF and the younger Port Kennedy and McLeod sites (Berta 1987; this volume). There are no late Iwingtonian records of Smilodon from Florida. The larger and more advanced species, S. fatWis (=S. populator of Berta 1985), first occurs at this time elsewhere in North America (Berta 1987; Lundelius et al. 1987). S. fatahs appears in Florida during the early Rancholabrean and is found there throughout the remainder of the Pleistocene. A large and possibly undescribed species of the machairodont cat Homotherium is represented at Leisey by a few isolated elements (Berta this volume). A partial skeleton of this species, including the skull and mandibles, is known from the correlative Haile 21A LF. Other fossils of this large Homotherium have been identified from Inglis 14 Haile 164 and possibly the late Blancan Santa Fe River 1 and Kissimmee River faunas. The large Homotherium present in Florida late Blancan and early Irvingtonian faunas is distinct from Dinobastis serus (see Berta this volume), a smaller sabercat known principally from the Rancholabrean, including the Reddick lA LF in Marion County (Waldrop 1974). The fossil record of the North American cheetah-like cat, Miracinonyx inexpectatus, has recently been reviewed (Van Valkenburgh et al. 1990). They reported M. inexpectatus from faunas of late Blancan through middle Irvingtonian age, including several Specimens from Inglis lA. Additional Florida records ofM. MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 47 inexpectatus not listed by Van Valkenburgh et al. (1990) are from Leisey (Berta this volume) and the late Blancan Santa Fe River 2. The large tremarctine bear, Arctodus pristinus, occurs in two late Blancan faunas and eight Irvingtonian faunas in Florida including Leisey lA (Emslie this volume). The oldest records ofA. pristinus in Florida are isolated teeth from the late Blancan Kissimmee River and Santa Fe River 1 faunas. Because this species is found throughout the Irvingtonian in Florida (Table 2), its presence does not place a fauna more precisely within this NALMA. There appears to be a chronological separation of tremarctine bears in Florida; Arctodus pristinus is found in the late Blancan and Irvingtonian and the smaller Tremarctos «#oridanus is restricted to the Rancholabrean. This may apply only in Florida, as the large bear Arctodus simus is widely distributed in North America during the Rancholabrean and T. ./loridanus has been reported from several western Blancan and Irvingtonian sites (Kurt6n and Anderson 1980). The river otter Lutra is an old World immigrant that first arrived in North America during the Irvingtonian (Kurt6n and Anderson 1980; Lundelius et al. 1987). The earliest previously reported North American records of Lutra are from the middle Irvingtonian Cumberland Cave and Port Kennedy Cave faunas (Kurt6n and Anderson 1980). The oldest well documented record of Lutra in Florida, and possibly North America as well, is from the Leisey Shell Pit LF. A well preserved mandible from Leisey 3B is similar in size to extant L. canadensis, whereas two associated upper teeth of Lutra from Leisey 1 A are distinctly larger than the modern species. A large extinct otter, L. parvicuspis, described from Cumberland Cave (Gidley and Gazin 1933), has been synonymized with L. canadensis by most recent authors (e.g. Kurt6n and Anderson 1980; Berta this volume). L. canadensis has also been identified from the Crystal River Power Plant, a close faunal correlate of Leisey. A large raccoon of the genus Procyon is present in many Florida late Blancan and Irvingtonian faunas, including Leisey (Procyon n. sp. in Table 2). Klein (1971) described the Procyon from Inglis lA LF (listed as "Procyon n. sp."by Webb and Wilkins 1984) as intermediate in size and morphological features between the large species P. rexroadensis from the early Blancan Rexroad LF (Kurt6n and Anderson 1980) and the living P. lotor. Morgan and Ridgway (1987) reported a large Procyon from the late Blancan St. Petersburg Times LF. A Procyon mandible from Leisey lA tentatively referred to P. lotor (Berta this volume) is also larger than the modern raccoon and is probably the same as the Inglis species. The only Irvingtonian record of Procyon listed by Kurt6n and Anderson (1980) was the small raccoon from Coleman 2A referred to P. lotor by Martin (1974). Two genera of seals found in Florida late Pliocene and Pleistocene faunas, the monachine phocids Monachus and Callophoca, may provide some useful biochronological information. With the exception of a single bone of the recently 48 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 37, PT. I, NO. 1 extinct Caribbean monk seal, Monachus tropicalis, from the late Rancholabrean Melbourne LF (Ray 1958), all other Florida records of Monachus are from the early Irvingtonian (Table 2). Monachus is known from two localities in the Caloosahatchee Formation of earliest Irvingtonian age, the De Soto Shell Pit LF and the Ortona Locks along the Caloosahatchee River, and two sites in the Bermont Formation of late early Irvingtonian age, Leisey Shell Pit and Rigby Shell Pit. The apparent absence of Monachus in Florida during the remainder of the Irvingtonian and most of the Rancholabrean may be an artifact of inadequate sampling of marginal marine faunas during this time interval. Monachine phocids also are present in four Florida late Blancan faunas, Brighton Canal, Kissimmee River, Macasphalt Shell Pit, and Richardson Road Shell Pit. These Blancan specimens appear to represent the large extinct genus, Cal/ophoca, which also occurs in Florida early Pliocene (late Hemphillian) faunas from the Bone Valley Formation in central Florida (Morgan 1994). Rodentia.-Martin (1969) reported several teeth of the giant beaver Castoroides from the presumed late Blancan Santa Fe River lB LF. However, the mammalian fauna from Santa Fe lB, like many of the Santa Fe faunas, consists of a mixture of late Blancan and Rancholabrean taxa (see more detailed discussion of Santa Fe sites below). Based on the absence of Castoroides from all other late Blancan and earliest Irvingtonian faunas in Florida, it is highly probable that the Santa Fe lB giant beaver teeth are Rancholabrean in age. Removing this single Blancan record, Castoroides first appears in North America during the Irvingtonian. The oldest well-documented occurrences of Castoroides in Florida are from the late early Irvingtonian Leisey Shell Pit and Crystal River Power Plant local faunas. Specimens of Castoroides from Apollo Beach in Hillsborough County are probably early Irvingtonian in age as well, although this site contains a mixed assemblage of Irvingtonian and Rancholabrean taxa. Morgan and White (this volume) describe the Leisey Castoroides as a new species, C leiseyorum. The more advanced species Castoroides ohioensis is common in Florida during the late Rancholabrean, particularly in faunas that sample freshwater depositional environments (Martin 1969). Pocket gophers of the genus Geomys are first recorded in Florida from the late Blancan Haile 15A and Macasphalt Shell Pit local faunas. These late Blancan specimens were referred to G. propinetis by Morgan and Ridgway (1987), an extinct species originally described from the early Irvingtonian Inglis lA and Haile 16A local faunas (Wilkins 1984). A small sample of pocket gopher teeth recently collected from the De Soto Shell Pit, a correlative of Inglis 14 is here referred to G. propinetis as well (Table 2). The Geomys sample from the Leisey Shell Pit LF is intermediate in size between G. propinetis and the extant southeastern pocket gopher G. pinetis, but otherwise is very similar to the living species (Morgan and White this volume). Apparently, G. pinetis evolved in Florida during the early MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 49 Irvingtonian, presumably derived from G. propinetis. Specimens of Geomys from the late Imingtonian Coleman 2A LF are indistinguishable from G. pinetis (Martin 1974; Wilkins 1984). There are two caviomorph rodents in the Leisey Shell Pit LF, the capybara Neochoerus sp. and the porcupine Erethizon dorsatum. Both are Neotropical immigrants that reached North America in the late Blancan following the beginning of the Great American Interchange. Two described species of Neochoerus are known from Florida late Pliocene and Pleistocene faunas, N dichroplax from the late Blancan (Ahearn and Lance 1980) and N. pinckneyi from the Rancholabrean (Ahearn 1981). Although the Neochoerus sample from Leisey lacks the diagnostic M3, the size and shape of the p4 differ from that of N. pinckneyi. More complete fossils are necessary to determine whether the Leisey Neochoerus is referable to N. dichroplax or represents a new species. The only Florida Blancan record of Erethizon is an associated palate and mandible from Haile 7C. Frazier (1981) described a small species, E. kleini, from Inglis lA. Three well preserved porcupine mandibles from Leisey are much larger than E. kleini, and appear to be indistinguishable from the living species, E. dorsatum. E dorsatum is also present in the early Irvingtonian Haile 16A and Apollo Beach local faunas and the late IfVinglonian Coleman 2A LF (Frazier 1981). Martin (1979) reviewed the evolutionary history of the cotton rat Sigmodon. Six species of cotton rats are recorded from Florida late Pliocene and Pleistocene faunas. The small, primitive species, S. medius, occurs in two Florida late Blancan faunas, Haile 15A (Martin 1979) and Macasphalt Shell Pit (Morgan and Ridgway 1987). The similar species, S. minor (conspecific with S. medius according to Kurt6n and Anderson 1980), is reported from eastern North America for the first time based on two teeth from the earliest Irvingtonian De Soto Shell Pit (Morgan and White this volume). The larger and more progressive species, S. curtisi, was recorded from the earliest Irvingtonian Inglis lA LF by Martin (1979) and also occurs in the correlative De Soto Shell Pit LF (Morgan and White this volume). Martin (1979) described S. libitinus from the late early Irvingtonian Haile 16A LF. Morgan and White (this volume) report S. hbitinus from the Leisey Shell Pit LF and two other correlative late early In'ingtonian faunas, Payne Creek Mine and Haile 21A. S. libitinus is intermediate in certain morphological features between S. curtisi from the earliest Irvingtonian and S. bakeri from the late Irvingtonian Coleman 2A LF (type locality) and several early Rancholabrean faunas (Martin 1979). The extant cotton rat S. hispidus is the typical species found in Florida late Rancholabrean faunas, although it first appears in the early Rancholabrean Daytona Beach and Haile 8A local faunas. The oldest arvicoline rodent known from Florida is the primitive muskrat, Ondatra idahoensis, from the earliest Irvingtonian Inglis lA and De Soto Shell Pit local faunas. 0. idahoensis occurs in western faunas of similar age, such as Curtis Ranch in Arizona (Repenning 1987), as well as slightly older late Blancan faunas 50 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 37, M. I, NO. 1 (Blancan V of Repenning 1987), including Borchers, Kansgs and Grand View, Idaho (the type locality). The larger and more advanced muskrat, 0. onnectens, is present at Leisey Shell Pit, as well as in the correlative Pool Branch and Payne Creek Mine local faunas from the Bone Valley Region in Polk County. 0. annectens is a rather long-ranging species characteristic of late early and middle Irvingtonian faunas (Nelson and Semken 1970; Martin and Tedesco 1976; Repenning 1987). Western early Irvingtonian faunas containing 0. annectens include Java South Dakota (Martin and Tedesco 1976; Martin 1989), Kentuck and Wathena, Kansas (Repenning 1987) and Sal)pa Nebraska (Martin and Schultz 1985). Two other genera of arvicolines are recorded from Leisey, the bog lemming Synaptomys and the vole Pedomys. About ten complete arvicoline teeth from Leisey are referred to Pedomys by Morgan and White (this volume). The Leisey Pedomys are very similar to a large series ofjaws and teeth from the slightly older ~ Haile 16A LF currently being described as a new species by Robert Martin (in prep.). A third sample of this same species occurs in the correlative Payne Creek Mine LF (see discussion below). Two teeth from Leisey are referable to Synaptomys sp. A similar sample of Synaptomys from Haile 16A also is currently under study by Robert Martin. The Leisey and Haile 16A Synaptomys appear to be related to S. australis, a large, extinct species present in Florida Rancholabrean faunas (Martin, pers. comm.). Perissodactyla.-Hulbert (this volume) describes the Leisey sample of the giant tapir, Tapirus haysii, and discusses the biochronology of the genus in Florida. A smaller, undescribed species of Tapirus is present in the earliest Irvingtonian Inglis lA and De Soto Shell Pit local faunas, the latest Blancan Haile 7C LF, and possibly several other late Blancan sites as well (Table 2). T. haysii is known from the Blancan and Irvingtonian in the western United States, but this species has a more restricted range in Florida where it has been identified from ten late early or middle Irvingtonian sites (Hulbert this volume). The tapir from the late Irvingtonian Coleman 2A LF, although represented only by postcranial elements, is within the size range of T. veroensis, the common Florida Rancholabrean species. The three species of Equus recognized in the Leisey Shell Pit LF (Hulbert, this volume) are of limited biochronologic use because of the chaotic state of the taxonomy of North American Equus. None of the Leisey Equus are definitely conspecific with named species in well-dated western faunas. The absence of the hipparionine horses Nannippus and Connohipparion, found in Florida Blancan faunas, is suggestive of a post-Blancan age for Leisey. The most common horse at Leisey, Equus "lei*i," occurs throughout the Irvingtonian in Florida. E. "kia)i" is very similar to, and possibly represents a small eastern subspecies of, E. scom, a common late Blancan to early Rancholabrean species with a wide distribution in MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 51 western North American (Winans 1989). The second most common horse at Leisey is an apparently undescribed form of the subgenus Hemionus. This subgenus is first known from the late Blancan of western North America (Skinner 1972), where it persisted through the Rancholabrean (E «*ancisci, Lundelius and Stevens 1970; Winans 1989). Other than Leisey, this new species is provisionally identified based on limited samples of isolated teeth from Pool Branch Apollo Beack and Flamingo Watenvay in Charlotte County. The rarest of the Leisey horses is E. "~aternus" which is much better represented at Haile 16A. Both the relationships and biochronological signficance of this species are poorly known. Artiodactyla.-Two species of peccaries occur in the Leisey Shell Pit LF, My/ohyus fossilis and Plat>gonus vetus. In his review of the Leisey tayassuids, Wright (this volume) refers the sample of Mylohyus to M. fossihs, a species typical of middle Irvingtonian through late Rancholabrean faunas in the eastern and central United States. Kinsey (1974) described the small Blancan species M. floridanus from the late Blancan Haile 15A LF. M. foridanus has since been reported from the late Blancan Macasphalt Shell Pit as well (Morgan and Ridgway 1987). The Leisey Mylohyus is larger than other specimens of late Blancan or Rancholabrean A*lohyus examined from Florida. Wright (this volume) notes that it is difficult to separate the various Blancan and Irvingtonian species of Plaosonus, most of which are larger than the common Rancholabrean species, P. compressus. Large specimens of Plaosonus from Florida late Blancan faunas (Table 2) generally have been referred to P. bicalcaratus (Webb 1974a; Morgan and Ridgway 1987). Wright (this volume) provisionally refers the Leisey Piaogonus to P. vetus, a large species known from many early and middle Irvingtonian faunas, including large samples from Inglis lA and Haile 21A. An even larger Platygonus from the late Ilvinglonian Coleman 2A LF and the early Rancholabrean Haile 7A LF is tentatively referred to P. cumberlandensis (Martin 1974; Wright this volume). The smaller species, P. compressus, appears in Florida during the early Rancholabrean. Camels are the most abundant large mammals in the Leisey Shell Pit LF, approached in numbers of individuals only by horses. Two camels have been idenURed from Idsey, Palaeolama mirijica and Hemiauchenia macrocephala (Webb and Stehli this volume; they use the species name H. seymourensis for the Leisey sample of this genus). H. macrocephala is a long-ranging species that first appeared in the late Blancan and survived until the end of the Pleistocene (Webb 1974b). A larger species, H. blancoensis, has been identified from several Florida late Blancan sites (Table 2; Webb 1974b; Morgan and Ridgway 1987). The occurrence of Palaeolama at Leisey represents one of the earliest North American records of the genus; only the sample from Haile 16A is older. The two major Leisey sites, Leisey lA and 3A, differ significantly in their camel faunas. Palaeolama is the most abundant large mammal at Leisey lA, outnumbering 52 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL- 37, PT. I, NO. 1 Hemiauchenia by more than two to one. In contrast, Hemiauchenia overwhelmingly dominates the large vertebrate fauna at Leisey 3A and Palaeolama is absent. Proboscidea.--The Leisey lA proboscidean sample is predominantly composed of the mammoth Mammuthus, with only a few, mostly juvenile, individuals of the mastodon Mammut americanum and several fragmentary cheekteeth and tusks of the gomphothere Cuvieronius tropicus (see Webb and Dudley this volume). Leisey 3A is almost devoid of proboscideans, whereas Cuvieronius is the most common proboscidean in Leisey Shell Pit 3. The presence of Cuvieronius in Florida faunas was once thought to indicate an early Irvingtonian or older age (Brooks 1968). However, subsequent discoveries confirm that Cuvieronius occurs in Florida from the late Blancan throughout the Irvingtonian and into the early Rancholabrean. Although Cuvieronius is probably the most ubiquitous proboscidean in Florida Irvingtonian faunas, most of the fossils consist of isolated and/or fragmentary remains. The only comparatively rich samples of this genus from Florida are in the early Irvingtonian Punta Gorda LF, Charlotte County (Brooks 1968; Webb 1974a; see discussion below) and the early Rancholabrean Daytona Beach LF (Edmund et al. in prep.). The Daytona Beach site is the youngest recorded Florida occurrence of Cuvieronius. Leisey Shell Pit lA has one of the richest known Irvingtonian samples of Mammuthus (see Webb and Dudley this volume). The Leisey mammoth teeth are intermediate in morphological features between teeth of M. meridionalis and M. imperator as defined by Maglio (1973). Webb and Dudley restrict M. meridionahs to Old World mammoths and refer primitive North American mammoths from the early Irvingtonian to M. hayi. Webb (1974a) and Webb and Dudley (this volume) also discuss a sample ofM. hayi from the Punta Gorda LF which is very similar to the Leisey Mammuthus. The late early Irvingtonian Mammuthus from Leisey and Punta Gorda are comparable to samples from the Gilliland LF in Texas and the Holloman LF in Oklahoma, and may be among the earliest mammoths in the New World. The next youngest Florida fauna containing a measurable sample of mammoths is the early Rancholabrean Bradenton LF. All Florida Rancholabrean specimens ofMammuthus are referable to the widespread species, M. columbi. Sirenia and Cetacea.- The Sirenia and Cetacea are the only groups of Leisey mammals not covered in the individual taxonomic papers. The Leisey Shell Pit LF represents the earliest well documented North American record of the manatee Trichechus. Specimens of Trichechus from Leisey lA consist of a partial skull cap (UF 87226), an isolated tooth (UF 87227), and the proximal humerus of a juvenile (UF 81514 ). Manatee fossils are more common at Leisey 3 and include a nearly complete skull in the National Museum of Natural History, a partial skull (UF 124557), a complete humerus (UF 135693), and a metacarpal (UF 129092). MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 53 Domning (1982) reported several supposed late Blancan manatee specimens from Santa Fe lB, and noted that they were very similar to the living species T. manatus. Subsequent study of the Santa Fe lB fauna (Morgan and Ridgway 1987 and discussion below) has shown that this site contains a mixture of late Blancan and Rancholabrean taxa. The abundance of manatee fossils in other Rancholabrean sites along the Santa Fe River suggests that the Santa Fe Trichechus is late Pleistocene as well. The Leisey Trichechus sample is currently under study by Daryl Domning. Cetaceans are rare at Leisey. Two isolated teeth of small delphinids from Leisey lA are tentatively identified as SteneUa (UF 84919) and Tursiops (UF 84629). Three associated vertebrae (UF 142239) from Leisey 3B represent a much larger delphinid similar in size to the pilot whale Globicep/mla. Biochronology of the Ikisey Lower Vertebrate Fauna.- There are several taxa of lower vertebrates from the Leisey Shell Pit LF, including sharks, turtles, and birds, that provide some information relating to the age of the site. There is no established biochronology for any of these groups, and thus the age data are not so precise as those provided by the better known mammals. Furthermore, several of these tan are restricted to Florida sites. Shark teeth are common in certain units within the late Pliocene and Pleistocene shell bed sequence of central and southern Florida, but very little has been published previously on Florida sharks of this age (Scudder et al. this volume). In his review of Florida fossil sharks, Tessman (1969) did not mention any specimens younger than samples from the early Pliocene portion of the Bone Valley Formation. Three extinct species of sharks, Ginglymostoma serra, Isurus hastalis, and Hemipristis serra, and the extinct ray Rhynchobatus sp. have been identified from the Leisey Shell Pit (Scudder et al. this volume). There are no published records of these species from other Florida Pleistocene faunas. All three of the sharks are known from the early Pliocene Bone Valley Formation (Tessman 1969), and 1. hastahs and H. serra have been reported from the Pliocene Tamiami Formation (Morgan and Pratt 1983). It is possible that the teeth of the extinct species of sharks and rays were reworked into the early Pleistocene Bermont Formation in the Leisey Shell Pit from underlying Miocene sediments. Most of the Miocene shark teeth from Leisey are watenvorn and have a different color of preservation, whereas two H. serra teeth from Leisey 1 A and one from Leisey 3B were collected in situ, are in excellent condition, and have the same state of preservation as the remainder of the shark teeth from this unit. The two teeth of Isurus hastahs from Leisey are broken and waterworn, and thus reworking from the underlying Miocene beds is a distinct possibility. A tooth of the extant shortfin mako shark, I. oxyrinchus, from the Leisey Shell Pit fauna apparently represents the first published fossil record of this species in Florida 34 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 37, Fr. I, NO. 1 (Tessman 1969). The age of the Ginglymostoma serra teeth from Leisey is uncertain owing to the rarity of this species in Florida fossil sites, although the specimens are not obviously reworked. Other Florida records of G. se.a are from the Miocene and Pliocene (Tessman 1969). As is the case with the mako sharks, a living species of nurse shark, G. cirratum, occurs in the Leisey fauna as well. Teeth of the living great white shark, Carcharodon carcharias, are relatively common at Lcisey. This shark also has been identified from two late Pliocene sites in the Pinecrest Beds, the Macasphalt Shell Pit LF in Sarasota County (Waldrop and Wilson 1990) and the Kissimmee River LF, and from the earliest Irvingtonian Caloosahatchee Formation at the Cochran Shell Pit in Hendry County (Scudder et al. this volume). The oldest published record of C. carcharias in Florida is from the Bone Valley Formation of early Pliocene age (Tessman 1969). The extinct giant white shark, C. megalodon, was common and widespread in Florida during the late Miocene and early Pliocene. The most abundant bony fish in the Leisey Shell Pit LF is the alligator gar, A tractosteus spatula, a species no longer found in the Florida peninsula (see Scudder et al. this volume). The closest living population of A. spatula is in the Florida panhandle (Wiley 1976). Despite its current absence from southern Florida, A. spam/a is common in many Pliocene and early Pleistocene vertebrate sites in the southern half of the state. The youngest record of A. spatula from peninsular Florida is the early Rancholabrean Oldsmar LF in Pinellas County (Scudder et al. this volume). Three turtles from Leisey provide some evidence for the age of the site. Auffenberg (1988) described a new species of small land tortoise, Geochelone mlynarskii, from the late Irvingtonian Coleman 2A LF. Meylan (this volume) refers the dwarf land tortoise from Leisey to this species, although he transfers it to the genus Hesperotestudo. Auffenberg (1988) noted that among members of the lineage of small land tortoises in Florida termed the incisa group from the Rancholabrean species H. incisa, the major evolutionary changes occurred between the Blancan and early Irvinglonian, and between the late Irvingtonian and Rancholabrean. The Leisey sample is most similar morphologically to the Irvingtonian members of the incisa group, tentatively referred to H. m/ynarskii (Auffenberg 1988; Meylan this volume). The most common freshwater turtle in the Leisey Shell Pit LF is Trachemys scripta, an extant species now absent from central and southern peninsular Florida (Meylan this volume). Leisey represents one of the earliest records of T. scripta. Specimens from the earliest Irvingtonian Inglis lA and De Soto Shell Pit faunas appear to be referable to the larger extinct species, T. platymarginata (synonymized with T. idahoensis by Jackson 1988). T. platymarginato originally was described from the late Blancan Haile 15A and Sante Fe River 1 faunas (Weaver and Robertson 1967), and is now known from several late Blancan faunas in the southern half of the state. MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 55 Meylan (this volume) documents the widespread occurrence of the alligator snapping turtle, Macroc/emys temmincki, outside of its modern range during the late Pliocene and Pleistocene. M. temmincki is not currently found south of the Suwannee River in northern peninsular Florida. Fossil alligator snapping turtles are known from the late Hemphillian Palmetto Fauna, the late Blancan Macasphalt Shell Pit and St. Petersburg Times faunas, and the earliest Irvingtonian De Soto Shell Pit LF, as well as Leisey (Meylan this volume). The youngest fauna from southern Florida containing M. temmincki is the early Rancholabrean Oldsmar LF. Several species of birds from Leisey are biochronologically useful (Emslie this volume). The small extinct 1004 Gavia concinna, was previously known in Florida only from the late Hemphillian Bone Valley Formation in central Florida. Emslie (this volume) identifies G. concinna from Leisey thereby extending the biostratigraphic range of this species in Florida by about 3 million years. Leisey is the type locality for the extinct condor, Gymnogyps ko/ordi (Emslie 1988). This species is also known from the early Irvingtonian Haile 16A LF. Earlier records for the genus Gymnogyps include the late Blancan Macasphalt Shell Pit LF and the earliest Irvingtonian Inglis 1 A LF (Emslie 1988; 19923). All other fossils of Gymnogyps from Florida and elsewhere in North America are Rancholabrean in age and are referable to the living species G. cal#brnianus (Emslie 1988). Emslie (this volume) refers a small sample of fossil turkeys from Leisey to Me/eogris leopoldi/M. anza, following the usage of Steadman (1980). The Leisey Meleagris is similar to the large sample from Inglis 1 A referred to M. leopoldi/Af, anza by Steadman (1980). The Inglis and Leisey turkeys are smaller than specimens of Meleagris from Coleman 2A, a sample recognized by Steadman (1980) as intermediate between the Inglis turkeys and Rancholabrean specimens of the living species M. gallopavo. Summary of Leisey Vertebrate Biochronology.- Knowledge of Florida Irvingtonian faunas has vastly increased over the past two decades to the point where Florida may be the most densely sampled geographic region in North America for the Irvingtonian Land Mammal Age. Owing to the lack of absolute dates, there is still a degree of uncertainty in correlating Florida Irvingtonian faunas within the state. Paleoecological and biogeographical factors magnify this uncertainty when Florida sites are compared to Irvingtonian faunas elsewhere in the United States. Despite these problems, the correlation of Florida Irvingtonian faunas both within and outside the state should be accurate within approximately 0.2 Ma. Four of the genera used by Lundelius et al. (1987) to define the Irvingtonian NALMA occur in the Leisey Shell Pit LF, including Smilodon, Lepus, Equus s.s., and Mammuthus. Other genera identified from Leisey that have their first appearance in the Irvingtonian are Nothrotheriops, Castoroides, Lutra, and Palaeolama. Among the Irvingtonian immigrant genera recorded from Leisey, 56 BULLETIN FLORIDA MUSEUM NAl-URAL HISTORY VOL. 37, PT. I, NO. 1 Mammuthus and Lutra are Old World in origin and Nothrotheriops is Neotropical. Smilodon. Castoroides, and Palaeolama evolved in North America, but nonetheless are important biostratigraphic indicators. Irvingtonian faunas also are recognized by the absence of characteristic Blancan genera such as Borophagus, Nannippus, Equus (Dolichohippus), and Rhynchotherium. All of these genera are known from Florida late Blancan faunas (Morgan and Ridgway 1987), but are absent from Leisey. The Leisey Shell Pit LF is younger than the earliest Ininglonian Inglis lA and De Soto Shell Pit local faunas (Table 2; Klein 1971; Webb 1974a; Webb and Wilkins 1984) based on the presence of Mammuthus and the absence of various Blancan holdover species found in the two older faunas, including the dwarf Florida form of Megalonyx leptostomus, Chasmaporthetes ossifragus, Trigonictis macrodon, and Capromeox arizonensis. Furthermore, Leisey records the first occurrence in Florida of at least five genera not presently known from earliest Irdnglodan faunas: Nothrotheriops, Lutra, Castoroides, Palaeolama, and Mammuthus. There are also four genera of rodents present at Leisey that differ at the species level from their congeners at Inglis and/or De Soto (in parentheses), induding Geomys pinetis ((3. propinetis), Erethizon dorsatum (E. kieini), Sigmodon libitinus (S. curtisi), and Ondatra annectens (0. idahoensis). Leisey is considerably older than the only other thoroughly studied Irvingtonian fauna from Florida, the late Irvingtonian Coleman 2A LF (Martin 1974). Leisey and Coleman share only a few diagnostic mammalian taxa, as the latter site actually more closely resembles early Rancholabrean faunas. Examples of typically Rancholabrean species at Coleman are Dide/phis virginiana, Holmesina septentrionalis, Neojiber alleni, and Tapirus veroensis. Leisey lacks Didelphis and Neofiber and has the older spec\es, H. floridanus and T. haysii. There are also two genera of rodents from Leisey that differ at the species level from their congeners or closely related genera at Coleman (in parentheses), Sigmodon libitinus (S. bakeri) and Pedomys n. sp. (Pitymys aratai). Ldsey and Coleman do share several long-ranging In'ingtonian species, including Canis armbrusteri, Arctodus pristinus, and Equus "leidyi: A more precise age refinement for Leisey is now possible based on comparisons with other Irvingtonian faunas from Florida, most of which were discovered during the past 20 years. Like Leisey, most of these faunas are younger than Inglis lA and older than Coleman 2A. These intermediate In,ingtonian faunas include Haile 16A, Pool Branch, Payne Creek Mine, Crystal River Power Plant, Rigby Shell Pit, Haile 214 and McI.eod Limerock Mine (see Table 2 and discussions of the individual faunas below). All of these faunas except McLeod appear to be late early Irvingtonian in age, and therefore are roughly correlative with Leisey and between 1.6 and 1.0 Ma. McLeod is somewhat younger that the other faunas, probably late middle Irvingtonian in age (between 0.8 and 0.6 Ma). MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 57 The presence of three species at Leisey that are restricted to the late Blancan and/or early In,ingtonian serves to further constrain the age of this fauna effectively ruling out a middle Irvingtonian age. The large glyptodont Glyptotherium arizonae occurs only in early In,ingtonian faunas in the western United States (Gillette and Ray 1981). In Florida, G. arizonae has been recorded from the earliest Irvingtonian Inglis and De Soto sites, as well as five late Blancan localities (Table 2). Leisey is the youngest Florida record of G. arizonae, and the only fauna in which this glyptodont has been found in association with Mammuthus. All occurrences of Pachyarmatherium leiseyi (Downing and White this volume) are from late Blancan and early Irvingtonian sites. Canis edwardii has been reported only from early Irvingtonian faunas (Kurt6n and Anderson 1980). Florida specimens of this canid are known from both the earliest Irvingtonian (Inglis and De Soto) and the late early Irvingtonian (Leisey, Crystal River, Rigby, and Haile 21A). At least three species of mammals found at Leisey appear to be restricted to late early ivingtonian faunas in Florida. The cotton rat Sigmodon hbitinus is known only from Leisey, Payne Creek, and the type locality Haile 16A LF (Martin 1979), all of which are late early Irvingtonian, These three faunas also share the same undescribed species of Pedomys (Martin in prep.). Although identified from only two Florida vertebrate faunas, Leisey and Pool Branch, Nothrotheriops texanus also appears to be restricted to the late early Irvingtonian. Elsewhere in North America, the biochronologic ranges of the canids Canis edwardii and C armbusteri do not overlap, with the fonner restricted to the early Irvingtonian and the latter found in the middle and late Irvingtonian. Their co-occurrence at Leisey and Haile 21A confirms that C armbrusteri first appears in the early Irvingtonian, at least in Florida. Megalonyx wheatteyi is typically a middle Irvingtonian species, including the Florida sample from McLeod (McDonald 1977). However, a skull and other specimens from Leisey appear to be referable to M. wheatleyi, rather than to the smaller Florida form of M. /eptostomus, typical of late Blancan and earliest Irvingtonian faunas. Leisey, Payne Creek, and Pool Branch all have the extinct muskrat, Ondatra annectens, a species found in late early and middle Irvingtonian faunas in the western United States. The large tapir, Tapirus haysii, also occurs only in the late early and middle Irvingtonian in Florida (Hulbert this volume). Analysis of several evolutionary lineages, in particular Smilodon and Hohnesina, helps to clarify the age of Leisey. The Leisey representatives of these lineages further strengthen evidence from other taxa that this site best fits in the latter half ofthe early Irvingtonian, between 1.6 and 1.0 Ma. Comparisons with Irvingtonian faunas in western North America indicate that Leisey is most similar in age to the Gilliland (Hibbard and Dalquest 1966) and Rock Creek (Troxell 1915) local faunas from Texas, the Holloman LF from 58 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 37, PT. I, NO. 1 X X X X X X X X X X X X i Table 3. List of mammals shared by three correlative late early Irvingtonian local faunas: Leisey Shell Pit Florida; Gillitand, Texas; and Holloman, Oklahoma. Only species that occur at Inisey and one ofthe two other faunas are listed here. For complete mammalian faunal lists from these sites see Table 1 for Leisey, Hibbard and Daiquest (1966) for Gilliland, and Dalquest (1977) for Holloman Species Leisey Gilliland Holloman Xenafthra Holmesina floridanus Glyptotherium arizonae Paramylodon harlani Nothrothenops texamis Camivora 1 x x l 1 1 1 1 X X X tx Canis edwardii Procron sp Homotherium sp. Lagomorpha Sylvilagus floridanus Perissodactyla X X X X X X X X X X X X X X X X Tapirus haysii X Equus scom or E. "lei*r' X Equus (Hemionus) sp. X Artiodactyla Platygontls vetus Hemiauchenia macrocephala Odocoileus sp. X Proboscidea Cuvieronius tropicus X Mammuthus d M. hayi X 1Equus 'leidyr mmorpbo,oveany Innam to E. vohime). Oklahoma (Dalquest 1977), the Kentuck, Nash, and Wathena local faunas from Kansas, the Sappa LF of Nebraska (Martin and Schultz 1985; Lundelius et al. 1987), and the Java LF from South Dakota (Martin 1973 1989). Sappa is the type fauna for the early Irvingtonian Sappan Subage (Schultz et al. 1978; Martin and Schultz 1985; Lundelius et al. 1987). Sappa, Java, and the three Kansas faunas mostly consist of small mammals, and thus correlation with Leisey is based either on absolute ages or comparisons with other faunas of similar age that have both large and small mammals. Among the sites listed above, Leisey has the most taxa in common with Gilliland and Holloman (Table 3). All three faunas record the association of the MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 59 glyptodont Glyptotherium arizonae (Gillette and Ray 1981) and a primitive Mammuthus (Hibbard and Dalquest 1966; Dalquest 1977; Webb and Dudley this volume). These probably represent some of the earliest records of mammoths in North America whereas G. arizonae is unknown in younger middle Irvingtonian faunas. The concurrent range zone of Glyptotherium arizonae and Mammuthus cf. M. hayi seems to occur only during a rather narrow interval of time in the late early Irvingtonian. Another age-diagnostic large mammal shared by these three faunas is the giant tapir, Tapirus haysii, a species restricted to late early and middle Irvingtonian faunas in Florida (Hulbert this volume). Leisey and Gilliland share several additional mammals that are found primarily in early Irvingtonian faunas, including the rare ground sloth, Nothrotheriops texanus, a medium-sized representative of the pampathere Holmesina floridanus, and the caidd Canis edwardii. Hibbard and Daiquest (1966) stated that the Gilliland LF was post- Blancan and pre-Cudahy in age, or in other words, early Irvingtonian as defined here and by Lundelius et al. (1987). Although Dalquest (1977) regarded Gilliland and Holloman as earliest Irvingtonian in age, the presence ofMammuthus indicates that these two faunas are younger than faunas such as Curtis Ranch now generally regarded as earliest Irvingtonian (Lundelius et al. 1987). Leisey and the correlative faunas mentioned above all are considered to be late early Irvingtonian in age (between 1.6 and 1.0 Ma). These faunas are somewhat younger than earliest Irvingtonian faunas (2.0 to 1.6 Ma) including: Curtis Ranch, Arizona; Inglis 1 A; and De Soto Shell Pit. Leisey is older than typical North American middle Ifvingtonian (=Cudahyan) faunas (1.0 to 0.6 Ma) including: the type Irvington fauna from California; Cudahy, Kansas; Conard Fissure, Arkang« Vera Texas; Cumberland Cave, Maryland; Port Kennedy Cave, Pennsylvania; and Hamilton Cave, West Virginia. BIOCHRONOLOGY OF FLORIDA LATE PLIOCENE AND PLEISTOCENE VERTEBRATE FAUNAS In the following section we present synopses of the most important Blancan and Irvingtonian vertebrate fossil sites from Florida, with the exception of Leisey which is discussed in detail above. Each synopsis includes a brief description of the location and physical setting of the site, discussion of the key mammalian tan, reference to other factors such as relative sea level position that pertain to its age, and citations to the most important published references. Figure 4 is a map of Florida showing the location of the Blancan and In'ingtonian vertebrate faunas discussed in the text. More complete information on these sites is available in the locality files of the UF Vertebrate Paleontology Collections. Following these synopses we present a brief review of the Rancholabrean NALMA in Florida. 60 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL- 37, Fr. I, NO. 1 Table 2 is a list of 128 species of biochronologically diagnostic mammals from the most important Florida late Blancan and Irvingtonian faunas, as well as composite faunal lists for the early and late Rancholabrean. We have limited the mammalian faunas listed in Table 2 to those represented by ten or more diagnostic 12!6~ 23 2 7 24 ~ 3 1920 04 1 7 13 10 0 Figure 4. Map of Florida showing location of Blancan and Irvingtonian vertebrate faunas discussed in text Late Blancan: 1. Santa Fe River 1,2,44 84 and 154 Columbia County, 2. Haile 15A, Alachua County, 3. St. Peterburg Times. Pinellas County; 4. Kissimmee River, Okeechobee County, 5. Brighton Canal, Highlands County; 6. Macasphalt Shell Pit Sarasota County, 7. Bass Point Waterway, Sarasota County; 8. El Jobean, Charlotte County, 9. Acline Shell Pit, Charlotte County; 10. Lehigh Acres, Lee County, latest Blancan: 11. Haile 7C, Alachua County; earliest Irvingtonian: 12. Inglis 14 Citrus County, 13. De Soto Shell Pit, De Soto County, 14 Forsberg Shell Pit, Charlotte County, late early Irvingtonian: 15. Haile 164 Alachua County; 16. Haile 214 Alachua County, 17. Crystal River Power Plant, Citrus County, 18. Leiscy Shell Pit, Hillsborough County. 19. Payne Creek Mine, Polk County, 20. Pool Branch, Polk County. 21 Rigby Shell Pit Sarasota County. 22. Punta Gorda, Charlotte County; middle Irvingtonian: 23. McLcod Limerock Mine. Levy County; late Irvingtonian: 24. Coleman 24 Sumter County. MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 61 species, which excludes several small, biochronologically significant faunas. These faunas will be briefly discussed after the summaries of the larger sites. Figure 5 is a comlation chart showing the relative stratigraphic position and age of the major Florida Blancan and In'ingtonian faunas discussed in the text. DuBar (1958) initiated the use of terrestrial vertebrate fossils for the age determination of Plio-Pleistocene shell beds in Florida; however, he was hindered by the limited diversity of the vertebrate samples available to him. Furthermore, 35 years ago paleontologists had only a limited understanding of Late Cenozoic MA AGE NALMA NORTH SOUTH FLORIDA FLORIDA0.0 - - a„ 2. RANCHO- ~ DEVILS DEN. REDDICK. MELBOURNE , SE.LNOLEFiELD. VEROAAREDON[JOa ICHETUCKNEE RIV. 1 CUTLEA. MONKEY JUNOLE 0-2 -- LABREAN a |DAYTONA BEACH I ~ | HAIE 7A, SA WIUISTON M, 38 1 | BFMDENTON | \0.4 - 01 COLEMAN 2A1 mEU - Ul - U r--7 -Ul 1 MCLEOD I O.8 - O -om Z ~ L-L 2 /618.- 8 z 0 - ,0- - APOLLO BEACH (5 HAILE 21A CRYSTAL RIVER LEISEY SHELL PIT, PUNTA GORDA POWER PLANT POOL BRANCH, PAYNE CAEEK S i RIGBY SHELL PIT 3 - - HAILE 16A - - DE SOTO SHELL PIT 1.8 - & INGUS ;A FORSBERG SHELL PIT Ul - Z zo- 8 HAILE 7C Z- < MACASPHALT SHEU- PIT HAILE 15A ACLINE SHELL PIT, KISSIMMEE _ SANTA FE RIV. 1 RIVER, BRIGHTON CANAL 14 - m ST. PETE, TIMES, LEHIGH ACRES Figure 5. Correlation chart showing relative position and age of the Florida late Pliocene and Pleistocenevertebrate faunas discussed in text. The faunas are divided into those from northern and southern peninsularFlorida. with the arbitrary boundary between the two regions placed at 28°N latitude. The faunas listedwithin a box are approximately equivalent in age, but their order in the box does not represent stratigraphic superposition. Vertical size of boxes expresses the range of possible ages ofthe sites enclosed in the box. 62 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 37, PT. I. NO. 1 mammalian chronology in Florida and elsewhere. Webb (1974a) summarized the chronology of Florida late Pliocene and Pleistocene mammals and provided faunal lists for the two Blancan andfour Irvingtonian faunas known from the state at that time. In the past decade, large and taxonomically diverse Mmples of Blancan and Irvingtonian vertebrate fossils have been collected from Florida in direct stratigraphic context with well known marine units (see Table 4) including: Pinecrest Beds (Macasphalt Shell Pit, Morgan and Ridgway 1987; Hulbert 1988a; Emslie 19924b; this paper), Caloosahatchee Formation (De Soto Shell Pit, this paper), and Bermont Formation (Leisey and Rigby Shell Pits, Hulbert and Morgan 1989; Webb et al. 1989; papers in this volume). Furthermore, the Late Cenozoic mammalian biochronology of North America has vastly improved over the past 20 years, thanks to the studies of Skinner and Hibbard (1972), Webb (1974a), Lindsay et al. (1975), Kurt6n and Anderson (1980), Repenning (1980 1987), Lundelius et al. (1987), and many others. BLANCAN There is a 2-million-year gap in the Florida terrestrial vertebrate record between the well known early Pliocene (late Hemphillian) faunas of the Bone Valley Formation (5.2 to 4.5 Ma) and various late Pliocene (late Blancan) faunas (2.5-2.0 Ma).. Although early Blancan terrestrial faunas are unknown from Florida (Morgan and Ridgway 1987), the marine Bee Ridge Fauna from Sarasota County in southwestern Florida (Morgan 1994) appears to be between 3.5 and 3.0 Ma in age (=Blancan III or IV of Repenning 1987). The Bee Ridge Fauna consists exclusively of cetaceans, pinnipeds, and other marine vertebrates that are not comparable with continental faunas of early Blancan age from western North America. The oldest faunas considered in our study are late Blancan in age (Blancan V of Repenning 1987). The two most widely cited reviews of Florida Pliocene and Pleistocene faunas list only two late Blancan vertebrate faunas from the state, Haile 15A and Santa Fe River 1 (Webb 1974a; Kurt6n and Anderson 1980). Reasonably complete mammalian faunal lists have been published for both of these sites (Webb 1974a; Robertson 1976). Morgan and Ridgway (1987) described the late Blancan St. Petersburg Times LF from Pinellas County along the central Gulf Coast. They also discussed several other smaller Blancan faunas and presented a brief review of Florida Blancan sites. Numerous recent publications have discussed the late Blancan vertebrate fauna from the Macasphalt Shell Pit in Sarasota County (Morgan and Ridgway 1987; Hulbert 1988a; Jones et al. 1991; Emslie 19924b). Table 4. Florida Blancan and Irvingtonian vertebrale faunas collected in stratigraphic superposition with or in association with marine geologic units. Formation Age Site Remarks Pinecrest Beds late Pliocene Macasphalt Shell Pit Collected in place from Unit 4 of Petuch (1982) withinTamiami Formation (2.5-2.0 Ma) Pinecrest BedsPinecrest Beds late Pliocene Kissimmee River Not collected in place, associated molluscan fauna typicalTamiami Formation (2.5-2.0 Ma) of Pinecrest BedsPinecrest Beds late Pliocene St Petersburg Times Collected in place immediately above Pinecrest BedsTamiami Formation (2.5-2.0 Ma) Pinecrest Beds late Pliocene Lehigh Acres Not collected in place, associated molluscan fauna typicalTamiami Formation (2.5-2.0 Ma) of Pinecrest BedsPinecrest Beds late Pliocene Brighton Canal Not collected in place, associated molluscan fauna typicalTamiami Formation (2.5-2.0 Ma) of Pinecrest Beds M O R G AN & H U LBER T: O VER VIEW O F TH E LEISEY SH ELL PIT LO C A L FAU N A 63 Pinecrest Beds late Pliocene Acline Shell Pit Collected in place from Pinecrest BedsTamiami Formation (2.5-2.0 Ma) Caloosaliatchee latest Pliocene De Soto Shell Pit Collected in place within Caloosahatchee FaFormation (2.0-1.6 Ma) Caloosahatchee latest Pliocene Forsberg Shell Pit' Collected in place within or underlying Caloosahatchee FinFormation (2.0-1.6 Ma) Bermont Formation early Pleistocene Ikisey Shell Pit Collected in place within Bermont Fm. (1.6-1.0 Ma) Bermont Formation early Pleistocene Crystal River Collected in place within Bermont Fm. (1.6-1.0 Ma) Power Plant Bennont Formation early Pleistocene Rigby Shell Pit Collected in place within Bermont Fm. (1.6-1.0 Ma) Bermont Formation early Pleistocene Punta Gorda Lf Collected in place above Bermont Fm. (1.6-1.0 Ma) ofWebb (1974a) 'The Forsbers Shin Pitand Punta Gorda locality of Waldrop and Wilson (1990) are the same site. Howeva. this is a different locality from the Punta Gorda Local Fauna of Webb (1974a) and Kurtkn andAnderson (1980). 4 = Gomphothere Site of Brooks (1968) 64 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 37, Fr. I, NO. 1 Santa Fe River 1.-The Santa Fe sites are river bottom deposits in northern peninsular Florida collected along an approximately 10 km stretch of the Santa Fe River, which forms the border between Columbia County on the north and Gilchrist County on the south (Fig. 4, site 1). The Santa Fe River 1 LF, including sites 1,14 and 18, was collected from a bend in the river less than 0.5 km in length. The bottom of the Santa Fe River in this region produces a mixture of Blancan and Rancholabrean vertebrates. It is not difficult to separate the faunas of these two ages because there is very little overlap between them with regard to chronologically significant mammals. Although the Santa Fe lB site was originally thought to be a purely Blancan assemblage (Webb 1974a), a re- examination of the material from this locality reveals the presence of several IKanchollrean tan, induding Megalonyx jefersonii, Holemsina septentrionalis, Castoroides ohioensis.and Mammuthus columbi. The Santa Fe River 1 site has produced one of the most diverse faunas of large mammals known from the late Blancan of Florida (Table 2), including at least 22 species. Blancan indicators include Borophagus diversidens, Canis lepophagus, Nannippus peninsulatus, Equus (Dolichohippus), Platygonus bicalcaratus, Hemiauchenia blancoensis, and Rhynchotherium praecursor. The co-occurrence of these taxa with the Neotropical immigrants Dasypus beUus (small Blancan form), Holmesina Jloridanus (small Blancan form), Glyptotherium arizonae, "Glossotherium" chapadmalense, and Titanis walleri indicates a post- interchange late Blancan fauna. Five species from the Santa Fe River 1 LF are characteristic of Florida late Blancan and earliest Irvingtonian faunas: Glyptotherium arizonae, the dwarf Flodda form of Megalonyx leptostomus, Chasmaporthetes ossifragus, Capromeryx arizonensis, and Titanis walleri. Santa Fe 1 is one of four Florida late Blancan localities in which Smilodon is present (Berta 1987), a genus that does not appear until the early Irvingtonian in the western United States (Lundelius et al. 1987). General discussions of the Santa Fe River fauna can be found in Webb (1974a), Robertson (1976), Kurt6n and Anderson (1980), and Morgan and Ridgway (1987). Taxonomic references to Blancan vertebrate taxa from the Santa Fe River 1 LF include Weaver and Robertson (1967) on the turtle Trachemys platymarginata; Brodkorb (1963) on Titanis walleri (type locality); Gillette and Ray (1981) on Glyptotherium arizonae; Robertson (1976), Edmund (1987), and Hulbert and Morgan (1993) on Holmesinajloridanuy, Kurt6n (1965) and Berta (1987) on Smilodon gracilis, Berta (1981) on Chasmaporthetes oss@agus; and MacFadden and Waldrop (1980) on Nannippuspeninsulatus. Blancan mammals also have been reported from three additional Santa Fe River sites. MacFadden and Waldrop (1980) recorded Nannippus ph/egon (=N. peninsulatus) from Santa Fe River 44 a fauna that also includes Equus (Dolichohippus), Capromeryx arizonensis, and Platygonus bicalcaratus. In their review of the Blancan mustelid Trigonictis, Ray et at (1981) described and figured MORGAN & HULBERT: OVERVIEW OF THE LEISEY SHELL PIT LOCAL FAUNA 65 specimens of T. macrodon from Santa Fe River 8A. Berta (1981) reported and figured a maxilla of the hyaenid Chasmaporthetes oss