0012-4966/03/0708- $25.00 © 2003 MAIK “Nauka / Interperiodica” 0349 Doklady Biological Sciences, Vol. 391, 2003, pp. 349–352. Translated from Doklady Akademii Nauk, Vol. 391, No. 3, 2003, pp. 426–429. Original Russian Text Copyright © 2003 by Leshchinsky, Averianov, Faingerts, Skutchas, Rezvyi. Since 1995, new unique data on Mesozoic verte- brates from Siberia have been obtained by the research- ers of Tomsk State University (TGU), the Zoological Institute of the Russian Academy of Sciences (ZIN), St. Petersburg State University (SPbU), and the Paleonto- logical Institute of the Russian Academy of Sciences (PIN). In particular, the Shestakovo complex of Early Cretaceous vertebrate localities (Ilek Formation, Kemerovo oblast) has been examined in detail, while the earlier investigation of these localities yielded only psittacosaurian remains [1–3, see also references in these papers]. The present paper considers preliminary results of studying a new assemblage of Early Creta- ceous vertebrates that was found in August 2000, by the researchers of TGU in the Ilek Formation on the right bank of the Bol’shoi Kemchug River in the Krasno- yarsk krai [4]. In August 2001, researchers of TGU, ZIN, and SPbU performed additional washing of 470 kg of rocks from the Bol’shoi Kemchug 3 locality (BK-3). This yielded new materials on Early Creta- ceous vertebrates, including amphibians, lizards, birds, and mammals which are scarce in the Mesozoic. The vertebrate assemblage from BK-3 is especially similar to the Shestakovo Assemblage from the Ilek Formation. Vertebrates from the BK-3 locality are briefly described below and compared with specimens from Shestakovo. The material from BK-3 is stored at the Paleontological Museum of Tomsk State University (PM TGU). Fishes are represented in BK-3 by scales, jaw fragments, and isolated teeth of the primitive bony fishes Palaeonisciformes indet. and Sinamiidae indet. The same fish taxa have been registered in Shestakovo. The sole amphibian specimen that has been discov- ered in BK-3 is a poorly preserved humerus of a cau- date amphibian (Caudata indet.). The bone is relatively short and most likely belongs to a special taxon with short limbs. In the Shestakovo locality, the caudate amphibian Kiyatriton leshchinskiyi was described on the basis of fragmentary specimens. Turtles are represented in BK-3 by indeterminable carapace fragments. In Shestakovo, turtles are also rep- resented by fragmentary remains; however, they have been identified as the primitive freshwater turtle Kir- gizemys sp. of the family Macrobaenidae. The preliminary determination of choristoderans from BK-3 is based on scarce and extremely poorly preserved jaws with teeth resembling those of Cteniog- enys from the Late Jurassic of Europe and North Amer- ica and Khurendukhosaurus from the Early Cretaceous of Transbaikalia. Lizards are rather abundant (several dozens of deter- minable specimens, mainly, fragmentary jaws) and diverse in the BK-3 locality. They mainly belong to the same taxa as that discovered in the Shestakovo 1 and 3 localities (Ilekia sibirica, Saurillodon tschebulensis, and Shestakovia voronkevichi). However, the varanoid lizard cf. Parviraptor sp. is present which has not yet been registered in Shestakovo. On the other hand, the new primitive gekottan that is represented by scarce finds in Shestakovo has not been found in BK-3. Crocodiles are represented in BK-3 by indetermin- able isolated teeth and vertebrae. In Shestakovo, croco- diles are represented by much better preserved speci- mens, including complete skulls of at least two taxa. Pterosaurians are represented in BK-3 by rather numerous isolated teeth and determined as Pterodacty- loidea indet. and ?Ctenochasmatidae indet. The first taxon is represented by teeth characterized by a wide triangular crown and asymmetrically distributed enamel-like tissue. The second taxon is represented by a sole subulate and curved tooth, whose crown is entirely covered with undulating enamel-like tissue. Similar teeth have been recently discovered in the Ber- riasian of Japan [5]. In Shestakovo, only one isolated pterosaurian tooth resembling that of Pterodactyloidea indet. from BK-3 has been found. GENERAL BIOLOGY A New Locality of Early Cretaceous Mammals in Western Siberia S. V. Leshchinsky,* A. O. Averianov,** A. V. Faingerts,* P. P. Skutchas,*** and A. S. Rezvyi*** Presented by Academician V.N. Bol’shakov February 10, 2003 Received March 6, 2003 *Tomsk State University, pr. Lenina 36, Tomsk, 634050 Russia **Zoological Institute, Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg, 199034 Russia ***St. Petersburg State University, Universitetskaya nab. 7/9, St. Petersburg, 199164 Russia