On a record of choristoderes (Diapsida, Choristodera) from the Lower Cretaceous of Western Siberia

Abstract

Fossil remains (fragmentary dentaries and vertebrae) of Choristodera indet. from the Lower Cretaceous Shestakovo 1 locality (Kemerovo Region, Russia) are described. The taxon from Shestakovo is characterized by primitive vertebral features (fused neural arches and centra of the cervical vertebrae, elongated dorsal vertebrae) combined with the presence of dentin folds at the tooth bases (advanced character typical of neochoristoderes). Phylogenetic relationships of the form from Shestakovo and other Choristodera are uncertain.