Geological Quarterly, 1998,42(2): 141 - 160 The first Polish find of Lower Paleocene crocodile Thoracosaurus Leidy. 1852: geological and palaeontological description Marcin ZARS!<l, Gwidon JAKUBOWSKI , Eugenia GA WOR-BIEOOWA Zarski M., Jakubowski G .. Gawor-Bicdowa E. (]99S) - The first Po] ish find of Lower Paleocene crocodile Tlloracosflums Leidy, IS52; geo]ogieal nnd palaeonto]ogica] description. Geo!. Quart., 42 (2); ]4]- ]60. Wor.;Ulwn. Skeletal remains of a crocodil e orthe genus nwracosflurus Leidy, 1852 were discovered by M. Zarski in Lower Paleocene gaizes in the neighbourhood of Kazimien Dolny. They consist ora part of the vCrlebrol column containing the la~t dorsal vertebrn, the sacrum and eight caudal verleb~. The ngc of the deposits WIIS dclennincd by means of micro- and macrofauna; they were dated as middle Danian. In the absolute chronological scale it was the period betw= n 64.5 and 62.5 m.y. ago. The study of pe lecypods and gastropods makes it possible to assumelhat thesca in which the crocodilian lived was a~halrow basin with IVllter temperature of about I S' C. The presence oftrce trunks in the laycreontaining tbccrocodilian skelc!on suggests closeness 10 land. The foraminifers occurring in the Grccnsnnd, the hard limestone "hardground" and the opokas were also studied. Mflrcin Zu.rs/.:i, Eugenia Gawor-Biedowa, Polish Geo/Ilgica/ fllSlilulr, Rukowird.a 4, ()()·975 Warszawa, Po/wrd; Gwidoll ja/.:ubowski, MuseulIl of Ifre Earlfr, Polisf, Academy of Scirnces, AI. Na Slwrpie 20116, 00-488 Warnawtl, Polalld (received: 06.02.J998; occrpud: 11 .05.1998). Key words: Lublin Upland, Lower Paleocet'le, crocodile, biostrntigraphy, taxonomy. INTRODUCTION The vicinity of Kazimierz Dolny has so far yielded only jaw fragments and individual teeth of mosasaurs, found in Cretaceous deposits (A. Sulimski, 1968; A. Radwariski, The skeletal remai ns of the crocodile were discovered by 1985). The fragment of Ihe crocodilian skeleton is also the M. Zarski in the neighbourhood of Kazimierz Dolny in 1995 first find of a representative of reptil es in Lower Paleocene during geological mapping for the preparation of the Detailed sediments. Geological Map of Poland, scale 1:50000, sheet Pulawy (M. The geological and palaeontological study of the croco­ Zarski. 1996). Thc remains were embedded in the wall of an dilian skeleton was carried out during 1997 under the super­ abandoned quarry in a gorge called Kamien ny 061, in Lower vision ofM. Zarski. Palaeontological research of the skeleton Paleocene sandy gaizes overlying the "residual lag" with and of the macrofauna was carried out by G. Jakubowski; E. phosphorites sensu M. Maehalski and I. Walaszczyk (1987) Gawor-Biedowa investigated the microfauna, whereas a (Hg. I). stratigraphic and palaeoecological study, which will be the It is the first find of crocodilian remains in Paleocene subject ofa separate paper, was carried out by M. Machalski. sediments in Poland. In 1845 C. Meyer described a fragment Moreover, belemnites were identified by S. Cidliriski and of the muzzle of a narrow-snouted Jurassic crocodile Machi­ lithological analyses were made by B. Gronkowska. mosaurus hugiiMeyer, 1845, coming from Czarnoglowy near The present paper shows the geological background of the Kamieri Pomorski (1. Ozik, 1997). crocodilian fi nd and comprises results of micropalaeontologi- Pel - Lower Paln~ema Crmg- Upper Moaslrlchtlan bad Ilmednm glaueonitic sandstone ~2%gpita opaku hardground with phosphorthr Fig. I. -ion and geoiogicnl setting oPcrocodilim mains A -location of Kmimierz Oolay against rhe mbp of Poland; B -unmd geological &etch showing the laionof the Ksmicnny D& exposure: C -geological don of the Kamimy Dd quarry Wwjai sytuacja geologicma maledskamzqk6w kmkodyh A -lokalida iejonu IhzirnhDolncgo; B -dc &om odlrryty z lohlimcjq oasImiwia Kamienay Wf; C -prd geologicmy kamieniodwmr Kamienny D6t cal and macropalaeontological investigations as well as the Mary* (Museum of the IMh, Polish Academy of Scien- pdaeuntological description of the skeIeton. ces) for consultations and bibliographical advice concerning Thecrocodilian remains arc: housed in the collection of the fossil and recent crocodiles. Moreover, fie authors wish to Polish Geological Institute in Warsaw, regisbation number hnIcIEarol Sabath, M.Sc, (Institute of Pdaeobiology ,Polish Mw.PIG 1639. I1 (on permanent display). Academy of Sciences), who drew the pic& of the crocodiIe, I Jan Zaj~czkowski(Polish GeologicdInstitute),whoprepared Acknowledgements. The authors wish to express their the computer dabation of the pictures, hszek Dwmik gratitude to the Directors of the Folish Geologid Institute, (Museurn of the lkth, Polish Academy of Sciences), who who enabled them b undertake the research project, to Pro- took the photographs, and Krystyna Marc& (Museum of the feasor Hakka Osmdlsh (Institute of PfmbioIogy, Polish Earth, Polish Academy of Sciences), who made the prepara- Academy of Sciences), Profam Eric Buffetaut (Universite tion ofthe crocodilian remains. 1 Pierre and Marie Curie* Paris) and Wmt-Pmfessor Teresa The first Polish find of bwcr Palcoccnc crocodile... 143 Fig. 2. Interpretations ofthe Cretaceouflertiar)r boundary in the Vitula Valley profile neat Kazimierz Dolny according to different nuthors Interpretacje granicy hda/hze~io~$dw pmfilu doliny Wisty kolo Kazimiena Dolnego wedhg rdinych auto& OWTWNE OF THE GEOLOGICAL STRUC'IWRE in nearby boreholes at G6ra PuIawskst and at Zykyn, repre- AmBRIEF SUMMARY OF PREVIOUS RESEARCH senting the uppermost Maastsichtian, were not recorded by K. Poiaryska (1967) in exposures in the neighbourhood of Ka- zimien Dolny. The existence of a stratigraphic hiat~scom- The investigated profiIe is situated within the limits of the prising the uppermost Maastrichtian was also recorded by H. Marginal Trough -a tectonic structure formed at the turn of J. Hansen et al. (1989). K. Poiaryska (1967) regarded the the Cretaceous and the Tertiary (A. M. hlichowski, 1974). Greensand as Danian (the Sochaczew Beds) and tbeoverIy ing The exposure lies in the southern part of this synclinorium, gaizes as Montian (the Pulawy Beds). A similar opinion was called the Lublin Trough and filIed with Jurassic, Cretaceows put forward by W. Krach (1981) and A. Blaszkiewicz (1966, and Paleocene sediments. The total thickness of these di- 1980). The majority of contemporary investigators regard the ments amounts to ca. 819 rn (M. hki,1996). The Maas- overlying gaizes as of Danian age (A. Radwariski, 1985; G. I. trichtian sediments are ca. 250 rn thick and in the vicinity of Abdel-Gawad, 1986; M,Machalski, I. Walaszczyk, 1987; H. G6ra Pulawska ca. 6&50 rn thick. The surface of the terrain J. Hansen et al., 1989) (Fig. 2). The authors of the present is partly covered with Pleistocene deposits, whose thickness paper assume that the CretaceousrSertiary boundary runs at ranges From several metres up to several tens of metres. The the top of the hard limestone (M.Machalski, M. hrskifide Maastrichtian and Paleocene sediments in the vicinity of M.~arski et aL, 1997). In the last few decades a considerable Kazimierz Dolny crop out on the surface (Fig. 1). They have amount of stratigraphic and geological research has been always been of interest to geologists. These formations have carried out with reference to the area under discussion (J. been studied by numerous investigators, for instance A. Mo- Liszkowski, 1970; D. Peryt, 1980; K. Wyrwicka, 1980; R. rawiecki (1925), R. Kongie1(1935,1950,1962), R. Kongiel, Marcinowski, A. hdwafiski, 1983, 1996; W. J. Kennedy, L. Matwiejewhwna (1937), L, Matwiejewbwna (19351, 8. 1993; A. Radwariski, 1996; M. Machalski, 1996). Putzer (1942) and W. Poiaryski (1938, 1948, 1962, 1974, 1997). W. Poksuyski (1938) was one of the first to introduce Depth (m) Llthologicalprofile the lithostratigraphic division of the outcropping Maastrich- tian rocks. He distinguished the following strata: level "x'- Quaternary comprising the upper Maastrichtian opoka series, level: "y" - 0.0-0.3 Loess. the hard limestone "hardground" overlying the opokas, and 0.3-2.8 Ice-dammed clays. level 'z" - the Greensand with phosphorite concretions, in 2.8-3.0 Silty sand. the uppermost layer of which he placed the CretaceoudTer- 3.s3.2 Pavement with pebbles of Paleocene gdizes. Maastrichtim limestones and cristalline rocks of Scandinavian provenanoe. tiary boundary (Fig. 2). The scl-caIled Greensand is a glau- conitjc sandstone laying between the hard limestone Pnleoccne mian) "hardground'hnd the top of "residual lag" (the phosphorite layer). Gaize rubble, grey-white. The Sandy gf ze, grcy. probIem of the Cretaceousflertiary boundary is con- Limestone, grey. troversial, because the Greensand contains mixed Cretaceous Smdy gaize, greym. and Tertiary macro- and micmfauna. An important contribu- Limestone, grey. tion to the understanding of the stratigraphic problems con- Sandy gaize, grey-green. Limestone, grey. the discussed sequence was by nected with made K. Glauconitic sandy gaize with single phosphorite%grey-green. Poiaryska (1 952,1965,1967) and K. Potaryska, W, Poiarys- Sandy gain? with phosphorites, green-grey. with remains of ki (195 I ), She placed the CretaceouslTertiary boundary at the the crocodilian skclcton. top of the hard Iimestone. The so-called Zyiyn Beds, present Glauconitic sandstone (Greensand) with phosphorites (phos- phorite layer -"residual lag"), brown-grccn. (1986) at NasiI6w and Bochotnica. The investigation of the foraminifers carried out by H. Gawor-BiedowaWeM. hki st d, 1997) tsstlfles