PRELIMINARY REPORT OF AN UPPER CRETACEOUS ELASMOBRANCH FAUNA FROM RYAZAN OBLAST, RUSSIA

Herein, we report the discovery of an abundant and diverse vertebrate assemblage containing chondrichthyan, actinopterygian, and reptile remains from the Upper Cretaceous. The fauna was recovered from south-east Ryazan Oblast, Russian Federation. The collection site is a sand quarry located near the village of Malyy Prolom, Shatsky District. The chondrichthyan assemblage here consists of neoselachians and hybodontiforms, the latter of which is represented by the Ptychodontidae, Hybodontidae, and Polyacrodontidae. The majority of the neoselachians are represented by multiple genera from lamniform families such as the Cretoxyrhinidae, Anacoracidae, Mitsukurinidae and Odontaspididae. Other chondrichtyan taxonomic groups such as the Orectolobiformes, Squaliformes, Synechodontiformes, and Rajaformes are also represented. This fauna furthers our understanding of the biogeographic histories of many Mesozoic shark groups in this part of Eurasia.