Small Vertebrates from the Late Cretaceous and Early Tertiary of the Northeastern Aral Sea Region, Kazakhstan
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See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/237020814 Small vertebrates from the Late Cretaceous and Early Tertiary of the northeastern Aral Sea Region, Kazakhstan Article in Journal of Paleontology · March 2001 DOI: 10.1666/0022-3360(2001)075<0390:SVFTLC>2.0.CO;2 CITATIONS READS 28 236 6 authors, including: Paul David Polly Zbyněk Roček Indiana University Bloomington The Czech Academy of Sciences - Institute of Geology 202 PUBLICATIONS 4,757 CITATIONS 103 PUBLICATIONS 1,902 CITATIONS SEE PROFILE SEE PROFILE Gregg F Gunnell Alexander Averianov Duke University Russian Academy of Sciences 218 PUBLICATIONS 4,415 CITATIONS 413 PUBLICATIONS 4,524 CITATIONS SEE PROFILE SEE PROFILE Some of the authors of this publication are also working on these related projects: Mesozoic tetrapods from the Volga region, Russia View project Palaeontology and Ichnology of the Ombilin Basin, Sumatra, Indonesia View project All content following this page was uploaded by Zbyněk Roček on 03 June 2014. The user has requested enhancement of the downloaded file. J. Paleont., 75(2), 2001, pp. 390±400 Copyright q 2001, The Paleontological Society 0022-3360/01/0075-390$03.00 SMALL VERTEBRATES FROM THE LATE CRETACEOUS AND EARLY TERTIARY OF THE NORTHEASTERN ARAL SEA REGION, KAZAKHSTAN E. G. KORDIKOVA,1 P. D. POLLY,2,3* V. A. ALIFANOV,4 Z. ROCÏ EK,5,6 G. F. GUNNELL,7 AND A. O. AVERIANOV8 1Kapchagay Geological Expeditions, 480008 Almaty, Kazakhstan, 2Molecular and Cellular Biology Section, Biomedical Sciences Division, Queen Mary and West®eld College, London E1 4NS, United Kingdom, 3Department of Palaeontology, The Natural History Museum, Cromwell Road, London SW7 6BD, United Kingdom, 4Paleontological Institute of the Russian Academy of Sciences, 117647, Moscow, Russia, 5Department of Paleontology, Geological Institute of the Academy of Sciences of the Czech Republic, Rozvojova 135, CZ-16500, Praha 6-Suchdol, Czech Republic, 6Department of Zoology, Faculty of Natural Sciences, Charles University, VinicÏna 7, 128 44 Prague, Czech Republic, 7Museum of Paleontology, University of Michigan, Ann Arbor 48109-1079, USA, 8Zoological Institute of the Russian Academy of Sciences, St. Petersburg, 199034, Russia ABSTRACTÐField work conducted in the northeastern Aral Sea Region, southwestern Kazakhstan has produced a large number of vertebrates from late Cretaceous and early Tertiary sediments. Included among these vertebrates are sharks, bony ®shes, amphibians, turtles, lizards, crocodiles, and dinosaurs. This fauna comes from three formations, the Turonian-Coniacian Zhirkindek, the Santonian- Campanian Bostobe, and the early Tertiary Akzhar formations. In this paper we describe the microvertebrate fauna. The Akzhar fauna consists only of marine sharks, one hexanchiform species (Notidanodon cf. loozi) and four lamniform species (Carcharias teretidens, Striatolamia striata, Otodus obliquus var. minor, and Palaeocarcharodon orientalis). These suggest a Paleocene age, most likely Selandian or earliest Thanetian. In addition to previously described components, the Bostobe fauna now includes a discoglossid frog and the lizard Slavoia cf. darevskii. This is the ®rst Mesozoic record of each in Kazakhstan and the latest record anywhere of the latter. The Zhirkindek fauna is now known to include a varanid lizard. INTRODUCTION acusticum posterius; fe, foramen endolymphaticum; fj, foramen URING THE Late Cretaceous and early Tertiary, Middle Asia jugularis; fm, foramen magnum; fp, foramen prooticum; fps, fo- D lay on the northeastern part of the Turan plate. Recent work ramen perilymphaticum superius; KGE, Kapchagay Geological in Kazakhstan and Uzbekistan provides an improved picture of Expedition; oc, occipital condyle; pdsa, prominentia ductus sem- Middle Asian faunas, demonstrating important ecologic and bio- icircularis anterioris; pdsp, prominentia ductus semicircularis geographic differences from contemporary upland faunas in Mon- posterioris; Sh, Shakh-Shakh locality; svj, sulcus venae jugularis; golia (Shilin and Suslov, 1982; Nessov and Mertinene, 1986; Nes- T, Tyul'kili locality. sov et al., 1994; Nessov, 1995; Averianov, 1997; Norman and All specimens are housed at the Kapchagay Geological Expe- Kurzanov, 1997; Kordikova, 1998; Archibald et al., 1998; Nessov dition of the Ministry of Ecology and National Resources of the et al., 1998). An expedition to the Lower Syr-Dar'ya Uplift in the Republic of Kazakhstan (Almaty). Casts of some described spec- north-eastern Aral Sea region of Kazakhstan was carried out in imens are housed at the Museum of Paleontology, University of 1995 by the Kapchagay Geological Expedition of the Ministry of Michigan and at Queen Mary & West®eld College, London. Geology of the Republic of Kazakhstan and the University of Michigan Museum of Paleontology. Vertebrates have long been GEOLOGICAL SETTING known from this area (e.g., Rozhdestvenskii, 1968), but little has been published about either faunas or biostratigraphy. The 1995 The Lower Syr-Dar'ya Uplift is north of the Syr-Dar'ya River expedition revisited classic localities, such as Shakh-Shakh, and and east of the Aral Sea. It lies along the Karatau thrust, which prospected several new areas. Material was collected by surface extends in a northwesterly direction from the Karatau Mountains prospecting and, in rich areas, matrix was collected, screen in the southern part of the region. The area is about 90 km north washed, and picked. Local sections were also measured. Chon- northeast of Dzhusaly, a railway station along the Syr-Dar'ya Riv- drichthyans, osteichthyans, amphibians, turtles, dinosaurs, croco- er (Fig. 1). Prominent features in the region are Shakh-Shakh diles, and lizards were recovered from the Zhirkindek, Bostobe, ridge, a long north-south trending outcrop that extends for about and Akzhar formations. Floras and faunas from these beds have 30 km (the Shakh-Shakh locality referred to in this paper is along been discussed (Rozhdestvenskii, 1968; Bazhanov, 1972; Shilin the ridge's southern half), Buroynak (to the north of Shakh- and Suslov, 1982; Shilin, 1986; Kuznetsov and Chkhikvadze, Shakh), Tyul'kili Hill (in the Kankazgan area), and Egizkara and 1987; E®mov, 1988; Prizemlin, 1990; Nessov et al., 1994; Nor- Bartusken, which are two semi-isolated hills to the northwest of man and Kurzanov, 1997; Kordikova, 1998), but the remains of Shakh-Shakh. We examined three fossil-bearing beds in this re- small vertebrates have received little attention. Here we report on gion: the Zhirkindek, Bostobe, and Akzhar Formations. Much of sharks, frogs, and lizards from these formations and provide a the area is overlain by a Neogene pebble conglomerate known as general overview of their geological setting. In this paper we use the Kokkuryum Formation. the Paleocene age Selandian following Knox et al. (1996). In their The lowermost unit that we discuss here is the Zhirkindek for- scheme, the Danian is NP1 to late NP4 (65.2±59.8 m.y.), the mation, which is composed of sands interbedded with clays and Selandian is NP4 to late NP6 (59.8±57.9), and the Thanetian is silts. At Tyul'kili Hill, where it is well exposed, it is about 45 m late NP6 to the base of NP10 (57.9±53.9 m.y.). thick (Fig. 2). There is at least one fossiliferous horizon about 18 AbbreviationsÐB, Bartusken locality; cp, crista parotica;E, m above the base. The formation has a diverse fauna including Egizkara locality; faa, foramen acusticum anterius; fap, foramen gastropods, bivalves, brachiopods, crustaceans, selachians, os- teichthyans, amphibians, lizards, trionychid turtles, crocodiles (Turanosuchus aralensis), and ornithomimid, tyrannosaurid, and * Corresponding author. e-mail: [email protected] dromaeosaurid dinosaurs (Fig. 3; Kordikova et al., 1996, 1997). 390 KORDIKOVA ET AL.ÐSMALL VERTEBRATES FROM KAZAKHSTAN 391 FIGURE 1ÐMap of Kazakhstan and the surrounding region showing localities yielding the material described in this paper. Also shown are the Dzharakuduk area in Uzbekistan and the Fergana basin area in Kyrgyzstan which have yielded contemporary Late Cretaceous terrestrial vertebrate faunas. Its ¯ora is dominated by ferns, pines, Sequoia, laurels, and Pla- Yalovach Formation in the Fergana Basin of Tadzhikistan (Solun, tanus (Shilin, 1986). These indicate a low-lying coastal or coastal- 1937; Vyalov, 1945a, 1945b; Nessov et al., 1994). The Bostobe marine environment. We have reservations about applying the and Yalovach have been interpreted as Santonian and early Cam- name ``Zhirkindek'' to these rocks but formal redesignation must panian in age (Archibald et al., 1998; Nessov et al., 1998; Kor- await detailed mapping. The lowermost Zhirkindek formation was dikova, 1998), which we follow here. The Bostobe fauna is sim- assigned a Turonian age by Pyatkov et al. (1967) based on forams, ilar to Baynshirenian and Barungoyotian faunas from Mongolia while the middle and upper parts of the Zhirkindek were consid- (Jerzykiewicz and Russell, 1991). ered Coniacian contemporaries of the Bissekty formation in Uz- Unconformably overlying the Bostobe is the thinner Akzhar bekistan based on the vertebrates and plants (Archibald et al., formation. In places it is almost 15 meters thick and is composed 1998; Nessov et al., 1998). of loose, light-colored sands and gravels capped with a layer of Overlying the Zhirkindek, probably conformably, is the Bos- phosphorite nodules (Fig. 2). The formation is exposed at the tobe formation. This unit is best exposed along Shakh-Shakh