Sauropod remains from the Middle Jurassic Itat Formation of West Siberia, Russia

摘要

Isolated sauropod teeth and caudal vertebrae from the Middle Jurassic Itat Formation of the Berezovsk coal mine, Krasnoyarsk Territory, Russia, are attributed to the endemic Asiatic eusauropod family Mamenchisauridae based mostly on phenetic similarity. The few large anterior teeth lack marginal denticles. In small, possible juvenile posterior teeth there are denticles on both mesial and distal crown margins. The anterior caudal vertebrae are deeply procoelous, while the posterior caudal vertebrae are amphicoelous, which is characteristic for the Mamenchisauridae. The Berezovsk sauropod remains represent the northernmost and westernmost record for the Mamenchisauridae and the first Middle Jurassic Asiatic eusauropod outside China.