Abundance and taphonomy of dinosaur teeth and other vertebrate remains from the Bostobynskaya Formation, north-east Aral Sea region, Republic of Kazakhstan

Abstract

Vertebrate microfossils, including abundant dinosaur teeth, recovered from a series of horizons in the Late Cretaceous (Turonian–Campanian) Bostobynskaya Formation (Bostobynskaya Svita), north-east Aral Sea region, Republic of Kazakhstan, display taphonomic characteristics consistent with deposition within floodplain-hosted assemblages. Teeth collected from the horizons confirm the presence of theropods, hadrosaurs and sauropods in the formation, consistent with previous suggestions of the dinosaur fauna. Compositional analysis of microfossil collections show that the material is characterised by low weathering and abrasion states, a high diversity of small fossils that represent aquatic, semi-aquatic and terrestrial taxa, and an abundance of resistant bioclasts, such as teeth. The sedimentology of the Bostobynskaya Formation is dominated by crevasse-splay and flood-event facies. New records from these sites document an important Late Cretaceous vertebrate fauna in an equally important and much understudied part of Central Asia.