New euselachian teeth from the Ladinian–Carnian interval of Guizhou and Yunnan Provinces, South China

A taxonomic study of four tooth genera of euselachian sharks from the Ladinian–Carnian interval of the Guizhou and Yunnan Provinces, South China is presented. They include one euselachian shark of uncertain affinity, two indeterminate neoselachian sharks and one potential hexanchid shark. These four taxa display non-durophagous feeding behaviour, including grasping-swallowing, grasping, tearing and cutting strategies. High-resolution micro-CT scans and 3D reconstructions reveal that Euselachii gen. et sp. indet. and Neoselachii gen. et sp. indet. 1 possess orthodont teeth. Euselachii gen. et sp. indet. exhibits a prominent longitudinal vascular canal, but lacks an ascending pulp cavity, while Neoselachii gen. et sp. indet. 1 features two longitudinal vascular canals and a vascular cavity that ascends into the main cusp. To our knowledge, this study provides the first three-dimensional documentation of dental vascularisation in Triassic chondrichthyans.