Rivista Italiana di Paleontologìa e Stratigrafia volume ruJ numero 2 tavole 1 pagine 183-192 Settembre 1992 oFrHEUppERHlfSiJÈ3'.8Îr'''f, È.""lfi |+"?UY"S-"S%T;'.NAVALLE' (UDINE, FRIULI-VENEZIA GIULIA, NE ITALY) \TITH REPTILE TRACK\TAYS GUIDO ROGHI* & FABIO M. DALLA VECCHIA'I Key-uords: biostratigraphy, Upper Triassic, Carnian, Tuvalian, *ln*tt, Southern Alps, palynology, vertebrate tracks, palaeoenvi- Riassunto. Vengono riponati nuovi dati e considerazioni sulla biostratigrafia e il paleoambiente di una sezione stratigrafica costituita da alternanze dolomitico-marnose del Triassico superiore affioranti nella Val Dogna (Udine, Friuli, NE Italy). In panicolare è stato inve- stigato un intervallo con uno strato contenente piste di rettili arcosau- romorfi terrestri. Nel livello sopràstànte, quello che diretramente ri- copre le impronte e' stata rinvenuta una abbondante associazione pa- linologica tuvalica (Carnico superiore) con Enzonalasporites aigens; Vallasporites ignacii, Patinasporites d,ensus, Zonalasporites cinctus, Pseu. doenzonalasp orites summn s, Samaropo/lenites speciosus, Camerosporites secdtus; Partitisporites spp. Evidenze floristiche e sedimentologiche in- dicano un clima arido e un ambiente di deposizione costiero soggerro . ri-ot"to "-...;^-; Abstrdct. New data and considerations about the biostrati- graphy and the palaeoenvironment of a section in the Late Triassic dolomitic-marly sequence which crops out in the Dogna valley (Jdi- ne, Friuli, NE Italy) are reported. In panicular a unit wìth a surface bearing tracks of archosauromorph terrestrial reptiles has been inve- stigated. In the layer immediately overlaying the track-beanng one, a rich palynological assemblage with EnzonaLasp orites vigens; Vallasp orí tes ignacii, Patinasporites densus, Zonalasporites cinctus, Pseudomzona" lasporites surnnlus, Satnaropollenites speciosus, Camerosporites secatus and Partitisporiter spp. was found, indicating a Tuvalian age (Late Car- nian). Microfloral and sedimentological evidence indicate a dry clima- te and a coastal depositional environment subject to repeated emer- sions. lntroduction. The Canale di Dogna (Dogna Channel), usually reported as "Val Dogna" (Dogna Valley), is an E-W oriented incision in the Julian Alps and is run through by the Dogna creek, near the village of Dogna, Udine Province (Fig. 1) Ladinian dolostones (Dolomia de1lo Sciliar), some poorly known units of Carnian age, and the Dolomia Principale (Hauptdolomlt of German aut- hors) outcrop in the Dogna valley (Selli, 1963; Jadoú et al., 1995). The discovery of reptile tracks in the dolomi- tic-marly sequence cropping out in the lower Dogna val- ley (Dalla Vecchia, I996a, b) creared new inreresr in this lithostratigraphic unit. The present nore concerns the stratigraphy, in particular the biostratigraphy, and the palaeoenvironment of the section containing the foot- prints. G. Roghi contributed the palynological work and F.M. Dalla Vecchia the palaeoichnological study; other parts of the account were written jointly. Stratigraphy and sedimentotogy. The well bedded alternations of black marls and grey and dark grey dolostones cropping out along the lower Dogna valley were attributed to the Monticello formation by Jadoul et al. (1995). They are considered lateraily equivalent or even coinciding wirh the Carniz- za Formation (fadoul et al., 1995, fig. 2) which crops out at the nearby Valbruna and Cave del Predil (former- ly Raibl) localities. These alternating beds appear to lie below the Dolomia Principale, but this is difficult to confirm because of the steep morphology of the valley. No biostratigraphical and paiaeoenvironmental data have been published about this formation in the Dogna valley. The Monticello formation is well exposed along the Dogna valley downstream from the aqueduct intake situated to the east of the small viilage of Chiout di Puppe. Near the second waterfall downstream from the intake the foliowing succession is exposed (from the top downwards; Fig. 2A): 3) well bedded grey dolostones alternating with black marls in tabular, centimetric-decimetric layers (about 70 m); in the lower part of this unit the pelitic intercalations are more frequent and there is often evi- dence of mud-cracking on the upper and lower surfaces Dipartimento di Geologia, Paleontologia e Geofìsica dell'Università degli Studi di Padova, Via Giotto 7,I-35737 Padova. Kà DOGNA Mt. lof gi Dogna Chiout ,./1962 _" ---1/-î\,//v !1 Cortina À/OR?HEAS?gRlV ITALY Trevìso fl F O 'lo 184 of the dolomitic layers; in the study area in the Dogna valley the sequence ends at a prominent ledge which may be related to a change in lithology; 2) grey dolostones in banks with faint and irregu- lar joints possibiy representing the "orizzonte di Me- stri" (Giannolla, pers. comm.; see Jadoul et al., î995) (about 20-25 m); in the upper part in a passage to the overhanging unit (3) there is a 1-3 cm-thick greenish do- lostone; 1) some metres of well bedded, tabular, centime- tric-decimetric alternations of grey dolostones and black marls, the lower limit of which we have not verified because unimportant for the scope of this paper. The reptile tracks occur in the middle part of unit 3 (Fig. 2A), in the valley floor on the north side of Dogna vailey, upstream from the intake of the aqueduct. The beds dip about 3O.SSW. The section containing the tracks is shown in fig. 2P. At the base of the section there is a breccia layer (DGA98) with millimetric clasts, followed by two layers of marly'dolomitic mudstone (DGA99-1OO). The track-bearing layer (DGA1OO) is a di- sturbed mudstone with spots of wackestone at the top and deep mud-crack fissures; microfossils are completely absent. The track-bearing layer is overlain by black silty marls (DGA101) which were sampied for palyno- morphs. Above this level there is a mainly marly unit with thin intercalations of sterile, black dolomitic mud- stones (DGAI02-1,03). The upper pan of the section G, Rogbi & F. M. Dalla Vecchia Location of the site comprises beds of fine grained dolostone, sometimes se- parated by very thin interwals of black silty marls; struc- tures indicating subaerial exposure (fenestrae with vado- se silt) are common at this level. Ostracods are the most frequent microfossils (DGA104, 107, 108 and 110) fora- minifers (Aulotortws?, Nodosariidae) are less common (DGA104, 105 and 110). The depositional environment could be a restric- ted lagoon, represented by beds with only ostracods, so- metimes more open (DGA110), which passed to a tidal flat represented by beds with fenestrae, fine grain dolo- mitization due to strong evaporation, perhaps stromato- litic lamination (DGA104 ) and with long lasting supra- tidal exposure represented by vadose silts. This environ- ment was involved in the repeated arrival of pelitic sedi- ment which was probably deposited in a reducing envi- ronment, indicated by a black coiour and the presence of well preserved palynomorphs. The lack of marine fossils in the carbonate layers of the lower part of the section, where black marls are prevalent, could suggest a brackish or even fresh water environment. The frequent subaerial exposures, even in the iayer with a more mar- ked marine influence (DGA110) are noteworthy. They rcstify to the osciliating emersion of the zone and are in agreement with the presence of terrestrial reptiles. The Monticello formation is considered to represent deposi- tion on the inner platform (iadoul et al., L995) and the existence of an emergent area to the S and SW of the Palynology and reptile trackuays in Dogna Valley C : MDST.PKST 5 & .9 WKST-PKST c : & M-W-P 185 DGAl 07 DGAl 06 DGA105 DGAl 04 DGA103 DGAl 02 DGA1O1 DGAlOO DGA99 o =@ o oE oA,îF ^NYórO Pd'E;.' ; c ! {@ (Y'Èq): --;S.^ = dE--E a3>- E ó,.€'-ò tvOs*,sàP?EF H;;=E =o-> Èó!t -:oÈ=+ - = I q À ì -! J;E:€= È?e ÈsE6E_3ÈÈfiù;È !éÈi.?pH--j3Èe E.iÈSÉ 8,:3:EEÈ EÈ:Sg l'ÈHÈ*fE*È*ESÈÍ óSÈoSatYùíHÈPÈÈPònFÈdó;ì::f* RBSÈÈS&8SèiEi'=9r- ò p c o.e ò x È È F o * È BÈg 3È B*RRRs SgeÈFF*óÈÉÉS*È Èìefi&$SS:FN&è @ o PALYNOLOGICAL ASSEI\,lBLAGE SEDIMENTOLOGJCAL STRUCTURES AND FOSSILS F'.) - A\S.h"-.ti."t'lliglapfii6sectionoftheobservedpanoftheMonticelloformationalongDognaCreek. 1,2,3:interualnumberl,_'b'- 2, 3 (see text). B) the section containing the layer with the reptile tracks. Legend: 1) dark grey breccia with millimetric clasts, 2) dark grey to black marly dolostone, 3) black silty marls, 4) grey to dark grey dolostone, 5) light grey dolostone with undulating or MDST : mudstone, \IKST : wackestone, PKST : packstone, M-\fl-P : bands of mudstone, wackestone andrfféorrlrf r^rnt.. pacKsrone. - FENESTRAE WITH VADOSE SILT v DESSTCATTON CRACKS (rvuD cRAcKS) 5 BIOTURBATION. (DISTURBED SÉDIMENT) V REPTILE PRINTS Dogna valley during the deposition of the CarnizzaFor- mation was suggested by the same workers (ibidem, p. 87). Vertebrate Paleoichnology. The reptile trackways were described by Dalla Vecchia (1996a, b). There are at least four trackways and two of them are 2.40 m and 2.80 m long. They were produced by a quadrupedal plantigrade reptile, with a pentadactyl pes 17-20 cm long aîd aterr^dactyl or, most probably pentadactyl manus at least 50o/o smaller than the pes (Fig. 3A,B; see also Dalla Vecchia, 1.996b, fig. 3-5). The free portions of the toes are rather short, nar- row and sharply pointed. Digit V is short, thin, placed rather posteriorly and is not laterally oriented but is curved forward; digits I-IV have similar lengths but digit III is the iongest and I the shortest (Fig. 3A,B; see also Dalla \y'ecchia, 1996b, fig. 3-5). In the best preserved trackway the pace rs 43-47 cm, the stride 67-72 cm and the width about 30 cm; the pace angulation of pedes is osrRAcoDS E 1 17-t fO oesrnopoos a- 7 ' & FOFAT\,4'N,FERS I . - BT'ALVTA [-] 4 6è PoLLENS A 5 about 100o. Tracks not strongly outwardly directed, no evidence of feet dragging and absence of tracks of the tail, of the chest and of the belly indicate a relatively erect posture and a non-sprawling gait. Therefore the trackmaker was well adapted to locomotion on land. The relation between tracks and mud cracks (Dalla Vec- chia, 1996b) shows that these reptiles walked across a surface on which mud was drying or had just dried (see Thulborn, 1990, fig. 5.19). Another bed surface with mud-cracks and prob- able reptile tracks occurs in the creek bed, between the intake of the aqueduct and the first waterfall downstream (R. Azzoia, pers. comm.). Unfortunately this bed, which is at a stratigraphically lower level, is at present covered by debris. Track morphology and, to some extent, the para- meters of the trackways are reminescent of those of the crocodiles (see Dalla Vecchia, 1996b, fíg.8) and suggest a phytosaur or primitive crocodylomorph affinity (Daila Vecchia. 1996b). r MDST-PKST ] tocm 1,86 G. Roghi & F. M. Dalla Vecchia b;= The tracks do not correspond exactly to any de- scribed ichnotaxon (Haubold, 1971., 1984, 1986; Olsen & Padian, 1986). Their formal description and the insti- tution of a new ichnotaxon is beyond the scope of this paper and will be made elsewhere (Dalla Vecchia, in progress). Crocodylomorphs are known from Upper Car- nian deposits but are relatively smali, delicate reptiles represented by poor remains (Long & Murry, 1995). Pri- mitive crocodylomorphs of the Late Triassic and Early Jurassic were small, cursorial animals. It is unlikely that the earliest crocodylomorphs were larger than the suc- ceeding Late Triassic and Early Jurassic forms and had a body shape and posture more similar to that of present crocodiles. The pes of primitive crocodylomorphs is functionally tetradactyl, with digit V reduced to a meta- tarsal spur (see Dalla Vecchia, 1996b, fig. Z). The posi Fig. 3 - Manus-oes set s from t he two main trackways. A) right set from trackway A (t' Dalla Vecchia, 1996b, frg. 1), light from rhe lefr Iower corner; B) right set (5th) from trackway B (ibident),light from the left side. Pictures taken from sili con rubber casts of the origi nal tracks. Scale bar: 10 crn. tion of digit V in the pes tracks from Dogna could be in agreement with its position in the primirive crocody- lomorphs but this digit is more strongly deveioped in those tracks. Phytosaurs were typical Late Triassic reptiles, with a distribution ranging from the Middle Carnian in North Carolina to the Rhaetian in Switzerland, Germa- ny, New Jersey and Connecticut; maximum diversity was reached during the Late Carnian (Tuvaiian) (Benton, 1995). Even if the general shape of the pes print is simi- lar to the reconstruction of a phytosaur footprint (Par- rish, 1986, fig. 4.9A), the pedal skeletons of Parasuchus Lyddeker, 1885 and Rutiodon tenuis Camp, 1930 (see Parrish, 1986, fig. 4.4) and Pseudopalatus pristinus Mehl, t928 (Long & Murry, 1995, Îigs 53, 55) do not corre- spond exactly to the footprints from Dogna valley, mainly in respect of the position and shape of digit V (Fig. 3; cf. Dalla Vecchia, 1996b, fig. 3). Therefore, com- parison should be made with a phytosaur with a digit V characteristically placed very posteriorly and such a phytosaur is not known amongst the available skeietal remains. A third possible trackmaker considered by Dalla Vecchia (1996b) is an aetosaur. Aetosaurs were typical terrestrial quadrupedal plant-eaters of Carnian to Norian times. The oldest remains are from the ?Middle Carnian of North America, the youngest are from the "Rhae- tian" of Argentina and England, with a higher diversity during Late Carnian-Early Norian (Benton, 1995, Long & Murry, 1995; Lucas & Fleckert, 1996). Large aetosaurs are usualiy reconstructed as plantigrade and have a short and rather posteriorly placed digit V of the pes, with a curved metatarsal Y. Stagonolepls Agassiz, 1844 and Pa- ratypotordx Long & Baiiew, 1,985 are Late Carnian aeto- saurs with a size comparable to that of the trackmaker of Dogna tracks (I-ong Ee Murry 1995). The rauisuchians are excluded as the potential trackmaker because of the different parameters of their trackways. The possibility remains that the trackmaker was an unknown taxon. Trackmaker length on the base of the body pro- portions of the well-known phytosaur Parasucbus, can be roughly estimated as slightly iess than 3 m. On the basis of the reconstruction of the aetosaur Stagonolepis the length was about 2.5 m. The morphological peculiarity of the tracks may make them useful for the biostratigraphic correlation of non-marine units (Haubold, 1986) and for correlation of the Monticello formation with non-marine formations. Palynology. The black silty marls (DGA 101; Fig. 28) just above the track-bearing surface were sampled for palynological investigation. A rich and very well preser- ved miospore association was found. Seventeen taxa have been identified and a quantitative analysis on more than 2OO isolated grains was made. In the sample, the miospore are organized in single grains (85%) and in te- trads (15%). Treatment of the monosaccate group fol- lows that adopted by Scheuring (1970;1978) and Brug- man (1983) and the specimens found are in agreement with the descriptions of these authors. Some problems exist in the taxonomy of the bisaccate group. The de- scriptions of Van der Eem (1983) and Brugman (i983) have been used for the identification of the circumpol- ies; taxonomy is problematic when the grains are organi- zed in tetrads. A detailed taxonomic treatment will be given in an account of the palynological study of the whole section. Palynology and reptile trackzaays in Dogna Valley t87 The results of the quantitative analysis are as follows: Circumpollen 560/o Unidentifiedbisaccatepollens 27o/o Monosaccate and Vesicate pollens 8Vo Alete bisaccate pollen 7o/o rok Taeniate bisaccate pollen 0.5o/o Trilete spores 0.5o/o The following taxa have been recognised (the recognised taxa are listed in Fig. 1 and the most significative miospore are illustrated in Plate 1): Monosaccate: - Enzonalasporites oigens Leschik, 1956 (Pl. 1, fig. 1) - Vallasporites ignaciileschik, 1956 (Pl. 1, Íig. 2-3) - Patinasporites d.ensus (Leschik, 1956) Scheuring, 1970 (PI.1, fig. 6) - Zonalasporites cinctus Leschlk, 1956 - Pseudoenzonalasporites summus Scheuring, 1970 (Pl.1, fig. a-5) Bisaccate: - Sarnaropollenites speciosus Goubin, 1965 (P1. 1, fig. 9) - Ovalipollis pseudoalatus (Thiergart, 1949) Schuurman, 1976 (Pl. 1, fts.7) - Chordasporites spp. - Lueckisporites spp. - Lunatisporites acutus Leschlk, 1956 - Klausipollenites sp. - A I i sp orit es / Fa I c ispori t es spp. Circumpolles: - Camerosporites secd.tus Leschik, 1956 (Pl. 1, fig. 12) - Partitisporites maljaukinae (K.laus, 1960) Van der Eem, i983 (Pl. 1, {is. I 1) - Partitisporites nnimundanus Leschik, 1956 - Partitisporites quadruplicis (Scheuring, L97A) Yan der Eem, 1983 - Corollina aff. sp. A (sensz Schuurman, 1.977) (P1. 1, fig. 10) The combined occurrences o[ Enzonalasporites ai- gens, Vallasporites ignacii, Patinasporites densus, Pseudo en- zonalasporites slirnrnus, Samaropollenites speciosus and Ca- rnerosporites secatus are indicative of Tuvalian age (Late Carnian). This palynoflora is nearly identical to that descri- bed by Visscher & Krystyn (1978) ín the Carnian-No- rian transition sequence of Monte Triona, Sicily, corre- sponding to the boundary between the ammonoid Tro- pites subbullatus and Anatropites bereichi Zones (Kry- styî, 1974, Tuvalian 2-3 boundary). A microfloral asso- ciation containing all the taxa found in sample DGA 1,01 was described from a Carnian evaporite succession in Albania (Cirilli & Montanart, 1994) at a stratigraphic level attributed to the Tuvalian. The same raxa are found from Litwin & Ash (1993) in the Chatham Group, Deep River Basin (North Carolina, USA), and are, with the exceptio n of Samaropollenites speciosus (Dunay & Fisher, 1924), present in the Chinie Forma- tion and Dockum Group (S\f USA). Fisher & Dunay (1984) reported the presence oÍ Samaropollenites concin' nus, a form similar to S. speciosus, in a microflora from the Blue Mesa of Arízona, which contains all the taxa found in sample DGA 101. 188 G. Rogbi G F. M. Dalla Wcchia Dunay & Fischer (1978) reported a microflora with Camerosporites secdtus, Enzonalasporites oigens, Pati- nasporites densus, Vallasporites ignacii and Brodispora striata (Pseudoenzonalasporites sumtnus and Sarnaropolle- nites speciosu.r are not present) in levels of the Opp.- nitzer-Kalk (Austria) of Tuvaiian age (Tropites subbulla- tus Zone). Following these authors, Brodispora striata has a particular biostratigraphic significance since it was found with the above mentioned association only in the Late Carnian Arden Sandstone of England (Clarke, 1965; Fisher, 1972; Warrington, 1970) and in some loca- lities of the Chinle Formation and Dockum Group of S\f USA (Dunay & Fisher, 1,974; 1979; Fisher and Du- nay, 1984). FIowever, Brodispora striata was not found in the Late Carnian microfloral assemblages of the Sout- hern Alps (this work), Sicily (Visscher Ec Krysryn, 1.978) and Albania (Cirilli & Montanart,1994). Therefo- re the presence of Brodispora s*iata could be attributed to palaeogeographical causes. In sample DGA101 a form very similar to Corolli- na sp. A, sensu Schuurman 1977 and Van F.we 1977 (: Círculina sp. A) has also been recorded as cf. Corollina aff. sp. A. The specimens are or3 nized in tetrads, have a subequatorial circular furrow, a smooth sexine and faint equatorial infrastriature; a distal pseudopore is absent, or is ill-defined (Pl. 1, fig. 10). Palaeogeography and Palaeoenvironment. The palynological assemblage reported here shows a noteworthy likeliness with the Onslow Microflora (Dolby & Balme, 1976). The latter is a mixed associa- tion with elements belonging to the Gondwana and to the Laurasia continents and is different to the high lati- tude boreal and austral microfloral associations. All the taxa found in sample DGA101 are present in the On- slow Microflora but in different proportions. Bisaccate pollen such as Sulcatisporites are prevalent in the On- slow Microflora, while circumpolles are most abundant in sample DGA101. Visscher & Van der Zwan (1981) identified three Late Triassic floristic zones: a northern one charac- terized by Camerosporites and Ooalipollis, a middle one wíth Camerosporites, Ooalipollis and Samaropollenites, and a southern one with Camerosporites and Samaropol- lenites. Since the DGA101 microflora includes Camero- sporites, Ovalipollis and Samaropollenites it belongs to the middle belt, known mainly from localities in North Africa. The DGA101 microflora consist aimost entirely of circumpolles, bisaccate and monosaccate pollens, which belong to the typical triassic conifers; only one spore was observed. The monosaccate forms have been found associa- ted with the conifer Brachypbyllum (Yan Konijnenburg- Van Cittert, 1971). The circumpolles show affinities with Cheirolepidaceae; in fact Corollina was found in association with the conifer Hirmeriella (Francis, 1983; Van Konijnenburg-Van Cíttert, 1.97 1). The pollen, particulary the circumpolles, are rypi- cal xerophytic elements, which indicate an arid climate (Cirilli & Montanarr,1994; Visscher et a1.,1994). Aridí- ty is also indicated by the total lack of miospore produ- ced by hygrophytic plants (ferns or equisetales). This is in agreement with the position of the Me- diterranean region near the palaeotropic, where the cli, mate was arid and warm during the Late Triassic (Ro- binson, 1973). The presence of gypsum in the Upper Carnian of Carnia (Pisa, 1,971) and of Aupa valley (Bian- chin et a1., 1980) is additional evidence of aridity (Hal- lam, 1984). The microflora is represenrative of the vegetation living at or near the site where the reptiles walked lea- ving their tracks. This is indicated by the relatively high number of tetrads, as these usually disarticulate during prolonged transport and generally form a very low pro- portion of a palynomorph association. Acknouledgements. '!le thank Sandro Venturini for the description of the thin sections and the help in the interpretation of the depositional environment. 'We are grateful to Maurizio Tentor and to the Gruppo Speleologico A.D.F. of Monfalcone (Gorizia) for the preparation of the thin sections, to Stefano Castelli for the pictures, to Nicola Michelon for the drawings and to Andrea Vorlicek for technical advices. Thanks to Piero Giannolla for the useful discussion concerning the stratigraphy of Dogna valley. The writers are grateful to Prof. G. 'Sfarrington and to Prof. M. Prosperi Evans who revised the English text. This work was sponsored by a M.U.R.S.T. grant (ex 40% V De Zanche;600lo Mietto). PLATE I The slide collection. Coordinates of the figured specimens were taken with the England Finder using Leitz 'Wetzlar no. 5345 with attached camera. All the slides are housed in the Dipanimento di Geologia, Paleontologia e Geofisica of the University of Padova. 1) Enzanalasporttes vigens I-eschrk, L956, (45 pm); Slide Dognal II, G 3l/4;2-3) Vallasporites ignaciiLeschlk, 1956 (48 pm); Slide Dogna 1 I1,V 4A/),;4-5) Pseudoen. zonalasporites sunmt{l Scheuring,1970 (3 8 pm); (4, single grain, Slide Dogna 1 Y, L 46/ 1,; 5, tetrad, Slide Dogna 1 V N 46); 6) Patinasporites densus (Leschik, 1956) Scheuring,1970, (4A pm), Slide Dognal III, K39/I;7) OoaLipollis pseudoaldlus (Thiergan, 1949) Schuurman, 1976 (ength 81 pm), Slide Dognal, lII,M 42/1.;8) Lueckisporites sp. (48 pm), Slide Dognal, S 48/3i9) Samaropollenrtes speciosus Goubin,1965, (ength eZ pm), Slide DognalI,534/3.I0)cf.Corollina aff.sp.A(sensuSchuurman,TSTT), (diameterof singlegrainintetradis33pm),SlideDognalIl,Ka1/\1.1) Partitisporites maljauhinae (Klaus, 1960) Van der Eem, 1983, (diameter in single grain in tetrads is 40 pm), Slide Dognal V,D 41,14; 1.2) Camero" sporites secatus Leschik, 1956, (45 pm), Slide Dognal IV, G 3I/4. Palynology and reptiLe tracktoays in Dogna ValLey 1ì 189 -*"-,. .., i$i* 3l'':WP 190 G. Roghi & F. M. DalLa Vecchia REFERENCES Benton M.J. (1995) - Late Triassic to Middle Jurassic extinc- tions among continental tetrapods: testing the pattern. In N.C. Fraser and H.-D. Sues (Eds) - In the Shadow of the Dinosaurs - Early Mesozoic Tetrapods, pp. 366-397, Cambridge. Bianchin G., Carulli G.B.,Frizzo P., Longo Salvador F., Man- tovani F., Masé G., Mezzacasa G. tr Semenza E. (1930) - Carta Geologica della zoîa rta il T. 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