AN EARLY IRVINGTONIAN AVIFAUNA FROM LEISEY SHELL PIT, FLORIDA Steven D. Emsliei ABSTRACT A new early Irvingtonian avifauna is reported from Leisey Shell Pit Hillsborough County, Florida Bones of at least 30 extant and 15 extinct tan are identified, including new species of spoonbill (Ajaia chione) and ibis (Eudocimus leiseyi). The avifauna is composed primarily of aquatic and wading species. with the earliest fossil occurrence of trumpeter swan (Cygnus buccinator), spoonbill, extinct flamingo (Phoenicopterus cope,), eagle (Amplibuteo sp.) and the teratorn (Teratorms merriami), and the latest occurrence of an extinct loon (Gavia concinna). The flamingo, eagle, a large teratorn (Teratomis cf T. incredibilis), and an extinct goose (Branta dickeyi) are also the first records ofthese tan in the eastern U. S. The avifauna is indicative of a paleoenvironment of a coastal lidal marsh or wetland with nearby mud flats and sandy shores. This habitat is common along the Gulf Coast of Florida today, but lacks the diversity of avian species that was present in the early Pleistocene RESUMEN Se reporta una nueva avifauna Irvingtoniana proveniente de los dep6sitos de conchuelas de Leisey, en el condado de Hillsborough, Florida. Se identificaron huesos pertenecientes a 30 especies actualmente existentes ya 15 especies extingui(las, incluyendo una nueva especie de espMula (Ajaia ch,one) y un nuevo ibis (Eudocimus leiseyi). La avifauna se compone primariamente de aves acuiticas y zancudas, con el fsil mas antiguo de cisne trompetero (Cygnus buccinator), espdtula, flamenco extincto (Phoenicopterus copei), aguila (Amplibuteo sp.), de teratorn (Teratornis mernam,), y adem4 la mis reciente ocurrencia de un somorgujo extincto (Gavia concinna). El flamenco, ~gllila, un gran teratorn Teratornis cf T. incredibilis), y un ganso extincto (Branta dickey,) representan tambi6n los primeros registros de estos taxones para el este de los Estados Unidos. Esta fauna es indicativa de un paleoambiente caracterizado por un humedal costero con influencia de mareas. o por un humedal con planicies lodosas y costas arenosas. Actualmente, este habitat es comin a 10 largo de la costa oeste de Florida aunque no posee la diversidad de especies de aves que existia en el Pleistoceno temprano. 1 The author is a Co~tesy Curator, Florida Museum of Natural History, University of Florida, P.O. Box 117800, Gainesville FL 32611- 7800, U.SA, and Assistant Professor in the Department Sciences, Western State College, Gunnison CO 81230, U.SA EMSLIE, S. D. 1995. An Early Irvingtonian Avifauna from Leisey Shell Pit, Florida. Bull. Florida Mus. NaL Hist. 37 PL 1(10):299-344. 300 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL„ 37, PL I, No. 10 INTRODUCTION Excavations at Leisey Shell Pit, Hillsborough County, Florida, have produced over 280 bird bones of at least 45 taxa. Most of the avifauna was recovered from one level in the pit, designated Leisey Shell Pit 14 where thousands of bones of terrestrial mammals and aquatic vertebrates were located and excavated by amateur paleontologists and personnel from the Florida Museum of Natural History (FLMNH), Gainesville. This portion of the shell pit has been dated to the late early Irvingtonian (1.5-1.0 Ma) based on associated vertebrate and invertebrate faunas, reversed paleomagnetism and strontium stratigraphy (Hulbert and Morgan 1989; Webb et. al 1989). In December 1986, two additional bone beds were uncovered in the shell pit 0.5 km west of Leisey lA. One of these beds, Leisey 34 produced hundreds of bones of camel (Hemiauchenia), a rich microfauna, and 25 bones and 11 taxa of birds. The second bed, Leisey 3B, contained a small collection of vertebrates including 10 bones and 5 taxa of bird. Leisey 3A and 3B also date to the late early Irvingtonian and are nearly comtemporaneous with Leisey lA (Morgan and Hulbert this volume). These three sites, as well as Leisey 1, 1B and 3, together comprise the Leisey Shell Pit local fauna (Hulbert and Morgan 1989). Leisey 1 and 3 refer to bones from the same quarry as Leisey lA or 18 and JA or 38, respectively, but with unknown provenience within the Inringtonian Bermont Formation. Lcisey 18 is located stratigraphically below Leisey 14 but within the Bermont Formation. The avifaunas of the Leisey Shell Pit LF together represent a unified avifauna (Table 1). An additional 10 bird bones were collected from Leisey Shell Pit 2 by amateur paleontologists and the exact provenience and age of these bones within the pit is unknown. These bones include three taxa not known from the Leisey Shell Pit LF (Tables 1 and 2). Their age could be either late early Irvingtonian or Rancholabrean. ACKNOWLEDGEMENTS This study would not have been possible without the help and cooperation of numerous amateur paleontologists and the ouners and supervisors at Leisey Shell PiL Those deserving particular thanks are Ralph "Tony" Estevez. Eric Fernandez, Frank A Garcia, Eric Hunter, C. E. "Bud~ Lcisey, Jr., Mickey Fowler, James L Pendergraft, James Ranson, Ronald J. Shrader and Donald O. WardL Assistance with loans of skeletal material and with museum collections was provided by Kenneth Campbell, Gary S. Morgan, Storrs Olson, Chris Shaw, and Ken WarheiL Stom Olson commented on an earlier version of the manuscript. Mary Ellen Aheam provided all photographs except Figures 2,4,5, and 7. EMSLIE: LEISEY SHELL PIT, FLORIDA, IRVINGTONIAN AVIFAUNA 301 METHODS Comparisons and measurements of skeletal material of Recent and fossil birds were completed at FLMNH and in the collections of Pierce Brodkorb (also housed at FLMNH1 Los Angeles County Museum of Natural History (LACM) and George C. Page Museum, Los Angeles University ofCalifornia Museum of Paleontology (UCMP) and Museum of Vellebrate Zoology (UCMVZ), Berkeley, National Museum of Natural History, Smithsonian Institution (USNM), Washington, D. C., American Museum of Natural History (AMNH), New York, Museum of Northern Arizona (MNA), Fl.g#.fr. All meawrements were taken with Vernier calipers to the nearest 0.1 mm Terminology follows that of Howard (1927). All fossils are deposited at FLMNH and arc catalogued with University of Florida (UF) numbers. Minimum numbers of individuals were calculated for catch taxon by counting the most common element ofthe same side. MNrs were determined separately for taxa *om Leiscy Shell Pit 1,14 18,3,3A and 3B and summed in Table 1. Table 2 provides MNrs for taxa from Lcisey 2. LEISEY SHELL PIT LOCAL FAUNA SYSTEMATIC PALEONTOLOGY Class AVES Order GAVIIFORMES Family GAV[IDAE Gavia concinna Wetmore 1940 Referred Material.- Leisey lA: distal left humerus, UF 63518; shaft left humerus, UF 86126; distal left tarsometatarsus, UF 82968. Description.- These specimens are from a small loon, slightly smaller than the smallest living loon, Gavia stellata (Table 3). The humerus, UF 63518 and 86126, differs from G. ste/lata in having a shallower impression of brachialis anticus and deeper facets on lateral ectepicondyle; G. immer has a relatively larger ectepicondylar prominence. The tarsometatarsus, UF 82968, differs from G. stellata, G. arctica, G. adamsii and G. immer by its relatively smaller distal foramen, and the posterior proximal border of the middle trochlea which extends farther proximally in the fossil specimen. Three fossil species of loons are known from the Pliocene of North America (Brodkorb 1963) and were compared to these specimens. The humerus of Gavia palaeo*tes and G. howardae are smaller than UF 63518 and 86126, especially in the shaft (Table 3). Specimens of G. concinna from the Bone Valley Formation, Florida agree with these specimens in size and characters, particularly with the extension of the border of the middle trochlea of the tarsometatarsus as described above. 302 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 37, PL I, No. 10 Table 1. Early Irvingtonian avifauna of Leiscy Shell Pit LF with total number of bones and minimum number of individuals (MNI) for each taxon. MNrs were calculated separately at each locality and summed below. Taxon No. Bones MNI Gavia concinna* 3 2 Gavia immer 2 1 Podilymbus podiceps 21 8 ZZLP. 00*0*nchos 4 211 84Phalacrocorax sp. or spp. Anhinga anhinga 2 1 11Anhinga sp. 1 2cZTe~Lius atbus 31 Egre#a cf E. tricolor 1 1 3-Egretta sp. Eudocimus leiser 1 1 Threskiornithinae, gen et sp. indet 1 Ajaia chione* 4 2 11Ciconia sp.* Clconia maltha* 9 2 Teratorms d T. incred,bilis* 1 1 Ten*ornis memami* 8 1 Gymnogps koford,* 6 1 1- cS~7Zclmr 5 1 1 2525nadensis 3 1 Branta dickqi* 2 1 Anabernicula gracilenta* 4 2 Ana3 crecea 5 3 A. crecca ot A. dhcors 13 A. plaryrhynchos 2 1 A. amencana 1 1 9-Anas sp. 6 3 Aythya americana A. manta 2 1 A. amencana or,4. marila 3 A. a»is 9 3 A. conans 2 1 A. aflinix or A. collaris 9 8- ~~e~ cf S. spectabili: 1 1 Bucephala albeola 5 3 Mergus serrator 1 1 1-Mergus sp. 17 - Anatidae 1- BZ;SS ~. B. linearus 1 1 EMSLIE: LEISEY SHELL Prr, FLORIDA. IRVINGTONIAN AVIFAUNA 303 Table 1 Continued. Taxon No. Bones MNI Aquita sp. 1 1 Amplibuteo sp.* 6 1 Accipitridae 1 Meleagns leopoldilanza* 5 2 Colinus sp. 2 211 Rallus sp Fulica americana 19 5 Grus canadensis 7 2 Grus sp.* 2 2 Recurvirostra sp.* 2 1 Limosa d L *doa 1 1 Alcidae, gen. et sp. indet 2 1 Phoenicopterus ruber 2 1 P. cope,* 2 1 Bubo virginianus 2 1 Con,us sp. 1 1 Aves, indet. «18 Total 281 80 *extinct taxon Table 2. Irvingtonian or Rancholabrean avifauna of Leisey Shell Pit 2 wilh total number of bones and minimum number of individuals (MNI) for each taxon. Taxon No. bones MNI Podilymbus podiceps 1 1 Phalacrocorax sp. 1 1 Anhinga anhinga 1 1 Ciconia maltha* 2 1 Bu~evoa~Jdcana 1 111 Jacana spinoia 1 1 cf. Icterinae 1 1 Aves. indet 1 - Total 10 8 *extinct taxon 304 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL- 37, PL I, No. 10 Discussion.- The referral of these specimens to the extinct loon Gavia concinna extends the geologic range of this species by 2-3 million years. Prior to now, G. concinna was known only from the Pliocene Bone Valley Formation and the Etchegoin Formation, California (Brodkofb 1963a). Chandler (1990) considers previously referred material from the San Diego Formation, California, to represent an undescribed species. After identifying these specimens, another specimen was found in the collections at FLMNH from Port Charlotte, Charlotte County, Florida. This bone, a distal left humerus (UF 22594), is from deposits dated to the Irvingtonian and has characters of G. concinna, including size (Table 3). Gavia immer (Brannich 1764) Referred Material.- Leisey 1: distal right humerus, UF 93272. Leisey 3: distal right tarsometatarsus, UF 124566. Table 3. Comparative measurements (in mm) offossil and Recent loon (Gavia) humeri to specimens from Leisey Shell Pit 1A and Port Charlotte, Florida. For each set of numbers the top row = mean f s. d, bottom row = range, m = male, f = female. Least Breadth Depth Distil Distal Species Shaft Shaft Breadth Depth G. arctica 7. 3 *.2 5.8 *.3 14. 3 *.5 9 .7 *.5 (342£ 17) 7.0-7.8 5.5-6.2 13.7-15.1 9.0-10.3 G. stellata 7. 0 *.5 5 . 8 *.5 13 .7 *.7 9. 4 *.7 (5rn, 9£ 1?) 5.8-7.7 5.1-6.6 12.5-14.7 8.6.11.1 G. adamsii 10 .8 8.7 20.4 14.3 (lm, 10 10.8 8.5-8.8 20.0-20.8 13.7-14.8 G. immer 9 . 5 * 1 .0 7.9 *.8 19. 0 * 1 . 8 13. 5 iE 1 . 2 (10rn, 100 8.3-11.4 6.6-9.5 16.9-22.4 12.1-15.7 G. palaeodyte# 7. 7 *.3 5 . 9 *.4 14 . 1 * 1 .0 9 . 7 *.3 (N=4) 7.3-8.0 5.4-6.3 13.0-15.1 9.4-10.0 G. howardael Range - - 12.0-14.4 8.8-9.3 (N=3) G. concinnal 8.3 *.3 6.4 *.5 15.1 *.7 10.5 *.7 (N=4) 8.0-8.6 5.9-7.0 14.3-15.7 10.0-11.5 UF 63518(Lcisey lA) 8.5 6.6 15.8 11.0 UF 86126 (I«eisey l A) 8.1 6.8 - - UF 22595 (Polt Charlotte) 7.8 6.4 15.9 11.2 ~Specimens Som Bone Valley. Florida (early Plio©ene) Data from Brodkorb (1955) EMSLIE: LEISEY SHELL PIT, FLORIDA, IRVINGTONIAN AVIFAUNA 305 Order PODICIPEDIFORMES Family PODICIPEDIDAE Podilymbus podiceps O.innaeus 1158) Refemd Material.- Leisey lA: 3 right coracoi(is, UF 69647, 80417, 80440; 6 left coracoids, UF 80418-80419, 80421, 84003, 85010, 87234; sternal end of left coracoid, UF 85179; 3 distal left humeri, UF 69644, 80441, 85011; proximal left ulna, UF 69400; distal left ulna, UF 85002; 2 left femora, UF 65812, 80415; distal right femur, UF 69637; right femur missing distal end, UF 80416; distal left tibiotarsus, UF 69640; distal right tibiotarsus, UF 80439. Leisey 3A: left coracoid, UF 95949; distal right humerus, UF 95950; left femur, UF 95888; proximal left tibiotarsus, UF 95898; distal left tibiotarsus, UF 95893; distal right tarsometatarsus, UF 95894. Podiceps sp. Referred Material.- Leisey IA: left coracoid with ends damaged, UF 80422; humeral end of left coracoid, UF 85134: left tibiotarsus, UF 80420. Leisey 3: proximal left tarsometatarsus, UF 129066. Description.- These specimens are intermediate in size between large individuals of Podiceps auritus and small individuals of P. grisegena and cannot be satisfactorily assigned to either species. Fossil grebes of this genus include P. ohgoceanus from the early Miocene of Oregon, P. pisanus from the middle Pliocene of Italy, P. subparvus from the middle Pliocene of California, P. discors from the late Pliocene of Kansas, P. parvus from the early to middle Pleistocene of California and Oregon, P. dixi from the late Pleistocene of Florida, and P. arndti from the late Pliocene of California (Brodkorb 1963b; Mumy 1967; Chandler 1990). Specimens of Podiceps subparvus and P. parvus were examined at LACM. P. suhparvus (LACM 5754) is approximately equal in size but not in relative proportions to UF 80420 (Table 4). The proximal articular surface appears relatively broader in UF 80420, and the distal shaft and condyles are more robust in LACM 5754. P. parvus (LACM 2546, 2220, 6923) compares most closely to UF 80420 except for a more robust shaft in the former (Table 4). P. arndti is smaller than P. grisegena (Chandler 1990) and has a relatively more robust tibiotarsus- than UF 80420 a*d 86276. P. di*ors is-known by only a single - tarsometatarsus and is near the size of P. nigricollis or female P. auritus (Murray 1967). P. dixi is an extinct grebe, larger than P. auritus, described by Brodkorb (1963b) from the late Pleistocene of Florida based on a proximal carpometacarpus. Steadman (1984) regards P. dixi to be a synonym of P. auritus because of a lack of diagnostic material. The specimens here, however, indicate Brodkorb (1963b) was correct in recognizing that a grebe larger than P. auritus occurred in the -1 306 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL„ 37, Pt I, No. 10 Pleistocene of Florida, but whether this grebe represents a distinct species or a large form of P. auritus cannot be determined. Order PELECANIFORMES Family PELECANIDAE Pelecanus cf. P. erythrorhynchos Gmelin 1789 Referred Material.- Leisey lA: head of right humerus, UF 81721. Leisey 3: distal right humerus, UF 124571; distal left tibiotarsus, UF 124572. Description.- These specimens are tentatively referred to species by their large size, equal to that of Pe/ecanus egthrorhynchos and much greater than that of P. occidentalis. P. halieus, an extinct species from the late Pliocene of Hagerman, Idaho, is known by only a proximal radius and is smaller than P. occidenta/is (Wetmore 1933). Discussion.- These specimens are the first fossil occurrence of an extant species of pelican in Florida. Pelecanus egthrorhynchos has been identified from late Pleistocene localities in California, Nevada and Kansas (Lundelius et al. 1983). Table 4. Comparative measurements (mm) of grebe (Pod,ceps) tibiolarsi. LEngth without 1£ast Least Cnemial Proximal Proximal Breadth Depth Distal Distal Specimen Crest Breadth Depth Shaft Shaft Breadth Depth Podicepi sp. UF 80420 90.5 8.4 9.1 4.0 2.7 8.2 8.2 P. subparvus LACM 5754 97.3 8.3 6.6 4.6 3.3 8.8 8.4 P. parvus LACM 2546 - 8.5 8.0 - - LACM 2220 - 9.5 9.3 5.1 3.5 - - LACM 6923 - - 9.7 9.2 EMSLIE: LEISEY SHELL PIT, FLORIDA, IRVINGTONIAN AVIFAUNA 307 Family PHALACROCORACIDAE Phalacrocorax sp. or spp. Refemd MateriaL- Ikisey lA: distal right tarsometatarsus, UF 125199. Leisey 3: upper mandible, UF 124567; proximal left humerus, UF 129068; proximal left ulna, UF 102549; right carpometacarpus, UF 124568; distal right tarsometatarsus, UF 102545; distal left tarsometatarsus, UF 102544. Leisey 38: complete right tibiotarsus, UF 116097. Description.- UF 124567 measures length, 51.6 mm; depth and breadth at anterior nares (closed), 6.1 and 8.8 mm. UF 124568 measures length, 68.2; proximal breadth and depth, 6.7 and 14.7 mm; distal breadth and depth, 7.4 and 8.0 mm; least breadth and depth of shaft, 5.3 and 3.8 mm. UF 116097 measures length, 117.4 mm; proximal breadth and depth, 12.8 and 16.2 mm; least breadth and depth of shaft, 7.7 and 5.4 min; distal breadth and depth, 13.5 and 12.7 mm. All specimens except UF 124567 are from a large cormorant, near the size of male Phalacrocorax auritus or P. penicillatus. UF 124561 is from a smdl cormorant, similar in size and characters to P. brasitianus, and may represent that species. Family ANHINGIDAE Anhinga anhinga CAnnaeus 1766) Referred Material.- Leisey 1: distal right ulna, UF 95621. Leisey 3A: right coracoid with ends damaged, UF 95896. Anhinga sp. Referred Material.- Leisey 3A: right tibiotarsus, UF 95948. Description.- This specimen is from a short-legged, robust individual compared to A. anhinga (Table 5), suggesting that two species are represented in the avifauna, but additional material is needed to verify the taxa. _Discussion.- The fossil history of Anhingidae is reviewed by Olson (1985) and Becker (1986).-Becker (1986) reports additional-localities for A nhinga grandis from the late Miocene of Florida, and an indeterminate large species from the early Pliocene (Bone Valley District) and late Pleistocene (Coleman 3; Ritchie 1980). The specimen from Coleman 3 is a distal ulna (UF 16664) and is not comparable 308 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL« 37, Pt I, No. 10 Table 5. C .[ 1 ' . .. {'' .. 1 Length without I./ast L~ast Cnemial Proximal Proximal Breadth Depth Distal Distal Specimen Crest Breadth Depth ShaR Shaft Breadth Depth Anhinga anhinga (646£ 1?) mean * s.d 84.5*2.4 10.2*0.3 15.4*0.7 5.2*0.3 4.2*0.1 10.3*0.4 9.1*0.3 Range 79.4-88.3 9.5-10.9 14.3-17.1 4.6-5.7 4.0-4.4 9.6-10.8 8.5-9.8 LEiscy 3A UF 95948 82.7 11.0 15.6 6.3 5.3 10.6 10.0 to the Leisey specimen. In addition, an unreported distal left humefUS (UF 102203) and distal left tibiotarsus (UF 102204) from the late Pleistocene Cutler Fossil Site, Dade Co., Florida, are also from a large anhinga. These records suggest that two lineages of anhinga are present in the fossil record of Florida. One lineage of large anhingas, beginning with A. grandis in the late Miocene, existed until the end of the Pleistocene. A second lineage of smaller anhingas is represented by the living species. Additional specimens are needed to determine systematic relationships of these taxa. Order CICONIIFORMES Family ARDEIDAE Ardea sp Refemd Material.- Leisey 3: left carpometacarpus lacking distal end, UF 123875; distal right tibiotarsus, UF 129061. Description.- UF 123875 is similar to Ardea herodias (n=7, UCMVZ) except that it is slightly more robust, and the anterior distal margins of the carpal trochlea extend relatively farther distally, with a longer and deeper depression between the margins than in the living species. It measures proximal breadth and depth, 9.0 and 21.2 mm; least breadth and depth of shaft, 7.3 and 5.6 mm. UF 129061 is from a heron most similar to Ardea, but much larger and probably EMSLIE: LEISEY SHELL PIT, FLORIDA, IRVINGTONIAN AVIFAUNA 309 represents an extinct species. It measures distal breadth and depth, 16.9 and 20.5 mm. Casmerodius albus (Linnaeus 1758) Referred Material.- Leisey lA: distal right femur, UF 65811; distal right tibiotarsus, UF 125198; phalang UF 69646. Egretta cf. E. tricolor gAuller 1116) Referred Material.- Leisey lA: distal right tarsometatarsus missing internal and middle trochleae, UF 82999. Description.- Compared to Egretta thula, E. caeurlea, and E. tricolor, this specimen is most similar to this last species in the position of the distal foramen and the relative size and position of the metatarsal facet. Egretta sp. Referred Material..- Leisey lA: right coracoid, UF 82965; sternal end of right coracoid, UF 85180; distal right tarsometatarsus, UF 80427. Description.- These elements are equal in size to Egretta tricolor, E. thula, and E. caerulea and probably represent one of these species. Family THRESKIORNITHIDAE Subfamily THRESK[ORNITHINAE Eudocimus leiseyi n. sp. Holotype.- Complete left tarsometatarsus, UF 80426 (Fig. 1). Collected August 1984. Type Locality.- Leisey Shell Pit IA, NW 1/4, SE 1/4, SW 1/4 Sec. 15, T, 32 S., R. 18 E.T Ruskin 7.5' Quadrangle; Hillsborough County, Florida. .Bermont Formation. Range and Distribution.- Late Blancan to late early Irvingtonian. This new species also is known from Macasphalt Shell Pit, Sarasota County, Florida (Emslie 1992). 310 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 37, Pt. I, No. 10 Diagnosis.- Recognized as Eudocimus by (1) single opening for proximal intertrochlear foramen and vascular foramen (these foramina are separate in Plegadis, also see Olson 1981), and (2) uneven borders of anterior metatarsal groove in sagittal plane (borders parallel in Plegadis). Differs from Eudocimus albus, E ruber and E peruvianus by: (1) distinctly smaller size and slender shaft (Table 6), (2) hypotarsus with single, centrally- placed tendinal opening entirely enclosed by bone (this opening is laterally-placed and is open posteriorly in other species of Eudocimus), (3) prominence lateral to external rim of external cotyla greatly reduced (this prominence is large in other species of Eudocimus and reduced in Plegadis). In all other features and proportions the specimen is similar to Eudocimus. Etymology.-- Named for Mr. Bud Leisey, owner of Leisey Shell Pit, who generously delayed mining operations for over a year in the portion of the shell pit where the bone bed was located so that paleontologists could excavate the fossils. ABC DJ.h Figure 1. Holotype left tarsometatarsus (UF 80426) of Eudocimus leiseyi n. sp. from Leisey 1 A (A) anterior view, (B) posterior view (1X bar=2 cm), and (C) proximal view, (D) distal view (2X bar= 1 cm) Table 6. Comparative measurements ofibis tarsometatarsi to£udoe,mus leiseyi n sp. from Ikisey Shell Pit lA Shaft Shaft Trochleae Trochleae Trochleae Trochleae Trochleae Trochleae Proximal Proximal L~ast Least Distal Internal Internal Middle Middle External ExternalSpecimen LEngth Breadth Depth Breadth Depth Breadth Breadth Depth Breadth Depth Breadth Depth Eudocimus albus (7A, 13't, 9?) 0*s.d. 92.0*8.0 11.5*0.9 11.7=:0.8 4.6*0.3 3.4*0.2 11.8*0.8 3.3*0.3 6.4*0.5 4.5*0.3 6.0*0.4 3.3*0.3 6.7=£0.5Range 79.1-105.0 10.0-13.6 10.7-13.3 4.0-5.2 3.0-3.9 10.4-13.5 2.7-4.1 5.5-7.2 4.0-5.2 5.2-6.8 2.6-4.0 5.8-7.8E. ruber (4A, 5?) EM SLIE: LEISEY S H E LL P m FLO R ID A , IR V IN G TO N IA N AV IFA U N A 311 0=Es.d. 83.4£6.1 11.0*0.7 11.3*0.7 4.6*0.3 3.2:10.2 11.4*0.7 3.2*0.2 6.80.6 4.3*0.2 5.7*0.3 3.2*0.2 6.51=0.6Range 76.1-95.5 10.1-12.1 10.6-12.4 4.3-5.1 2.8-3.6 10.5-12.6 3.0-3.6 4.6-6.7 4.14.8 5.3-6.3 3.0-3.6 6.0-7.8Phimosus infuscatus (USNM 190315, ?) 57.4 9.5 10.1 4.0 2.5 9.7 2.7 3.1 3.5 4.9 2.3 5.6Mesembrinibis cayennensts (USNM 345762, A) 64.1 10.9 10.7 4.5 3.6 11.0 3.2 5.6 4.1 5.4 2.9 6.1Theristicus melanopsis (UCMVZ 125155, A) 72.5 13.8 12.6 5.1 3.5 13.4 4.9 4.9 5.1 6.5 3.1 6.3T. caudatus (UCMVZ 94065, A) 79.4 14.2 13.1 5.7 4.3 13.7 4.3 5.7 5.0 6.8 3.6 5.7E. leiseyi UF 80426 77.9 8.8 9.5 3.6 2.7 9.6 2.6 4.6 3.5 4.5 2.9 4.8Plegadis gracilis UCMP 45088 - 8.0 - 3.4 - 312 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 37, PL I, No. 10 Discussion.- Three fossil ibis have been described from the New World: Theristicus wetmorei and Eudocimus peruvianus from the late Pleistocene of Peru (Campbell 1979) and Plegadis gracilis [=P. pharangites (Olson 1981)] from the late Pliocene of Texas (A. H. Miller and Bowman 1956). Three other bones from the early Pliocene Bone Valley Formation of Florida, and a distal tibiotarsus from the early Pliocene Lee Creek, North Carolina, have been referred to Eudocimus sp. (Brodkorb 1972; Olson 1981). These bones are as large or larger than E albus and are not comparable to UF 80426. Eudocimus leiseyi is the smallest species known for this genus and is smaller than Plegadis falcinellus or P. chihi. Only the fossil spedes P. pharangites approaches the size of E leiseyi. The former is known by a proximal tarsometatarsus, carpometacarpus, and distal ulna from Cita Canyon, Texas (Miller and Bowman 1956), and by two distal tibiotarsi and a coracoid from Rexroad, Kansas (Collins 1964). It is recognized as Plegadis by characters given by Collins (1964), and differs from E. leiseyi and is most similar to Recent Eudocimus and Plegadis by characters of the proximal tarsometatarsus given above. THRESKIORNITHINAE, indet gen. et sp. Referred Material.- Leisey 3: proximal right tibiotarsus, UF 123999. Description.- This specimen is from an ibis similar in size to Plegadis chihi, but is too fragmentary for generic or specific identification. Subfamily PLATALEINAE Ajaia chione n. sp. Type Specimens.- Holotype, distal right tibiotarsus, UF 82996 (Fig. 2). Paratypes, distal right tibiotarsus, UF 82967; proximal left tarsometatarsus, UF 82997; distal left tarsometatarsus lacking external and part of middle trochleae, UF 69645. Type Locality.- Leisey Shell Pit lA, NW 1/4, SE 1/4, SW 1/4 Sec. 15, T. 32 S., R. 18 E., Ruskin 7.5' Quadrangle; Hillsborough County, Florida. Bermont Formation. Range.- Known only from the type locality, late early Irvingtonian. Diagnosis.- Recognized as Ajaia and differs from Platalea by (1) smaller size (Table 7), (2) tarsometatarsus in posterior view with internal trochlea angled less posterior-externally, (3) tibiotarsus with narrower intercondylar fossa, and (4) EMSLIE: LEISEY SHELL PIT, FLORIDA IRVINGTONIAN AVIFAUNA 313 A D E -C Figure 2. Holotype distal right tibiotarsus (UF 82996) ofAJata chione n. sp. from Leisey 1 4 (A) anteriorview, (B) distal view. Paratypes, proximal left tarsometatarsus (UF 82997 ), (C, anterior), and distal lefttarsometatarsus (UF 69645) in anterior (D) and posterior (E) views (1.5X bar=1 cm). Table 7. Comparative measurements of spoonbill (Platalea and Ajaia) tarsometatarsi to A. chione n. sp. from Leisey Shell Pit 1 A Distal Distal Distal Shaft Shaft Trochleae Trochleae Trochleae Proximal Least Least Internal Internal MiddleSpecimen Breadth Breadth Depth Breadth Depth Depth P. leucorodia 16 .0 6 .2 5 . 5 4.4 9 .3 8 . 3 (USNM 491329) P. alba 16 .0 6 .0 5 .4 4 .4 9 .6 8 .6(USNM 558417) A. ajaja (5rn, 7?) meand=s.d 14.5*0.6 5.8*0.3 4.5*0.3 4.1*0.1 8.2*0.4 7.8*0.4 Range 13.6-15.5 5.5-6.5 4.1-5.0 3.9-4.3 7.7-9.1 7.3-8.6 A. chione UF 82997 16.1 - UF 69645 - 6.8 5.1 4.2 7.8 8.0 internal medial border of shaft of tibiotarsus more steeply angled proximally from the anterior proximal edge of the internal condyle to the shaft. Differs from Alaia ajaja by tibiotarsus with (1) relatively larger and rounderdistal foramen, (2) external condyle less robust, (3) intercondylar fossa relatively 314 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 37, PL I, No. 10 broader (but not as broad as in Platalea), and (4) proximal tendinal foramen located more medial with relatively more distinct medial border extending proximally on shaft. Tarsometatarsus with (1) larger distal foramen in posterior view, (2) distal foramen angled more dorso-ventrally than proximo-distally so that the opening is more visible in anterior view, (3) metatarsal facets relatively larger. Etymology.- From Chione, the most common genus of mollusk in the bone bed deposit at Leisey Shell Pit lA. Discussion.- This material represents the first fossil spoonbill to be described from North America, and the only fossil material known prior to the late Pleistocene. Bones of Ajaia ajaja have been reported from late Pleistocene deposits in Florida (Woolfenden 1959), California (Howard 1930), and Peru (Campbell 1979), and it is possible that A. chione is the direct ancestor of the living species. Family CICONIIDAE Ciconia sp. Referred Material.- Leisey 3: humeral end of left coracoid, UF 123869. Description.- The breadth and depth of the coraco-humeral surface measures 11.0 and 19.4 mm; the internal border of this surface is steeply angled in A