Original paper

Purported latest bone of a plated dinosaur (Ornithischia: Stegosauria), a "dermal plate" from the Maastrichtian (Upper Cretaceous) of southern India

Galton, Peter M.; Ayyasami, Krishnan

Abstract

A stegosaurian "dermal plate" was reported from the Kallamedu Formation (Upper Cretaceous, Maastrichtian) of southern India. However, histologically the dermal plates of stegosaurs, typified by Stegosaurus (Upper Jurassic, USA), have a thin outer cortex enclosing very cancellous bone having large vascular spaces. The Kallamedu fragment of eroded compact bone has no cortex and is probably from a sauropod dinosaur. Bones found in situin this formation typically disintegrate very quickly pon exposure to the air, but this bone is well preserved, although worn. It was found as float in a stream bed, indicating that there is a stratum upstream with well-preserved bones, that is still to be discovered in the Maastrichtian of southern India. Stegosaur remains from the underlying Coniacian (Upper Cretaceous) of southern India represents the most recent osteological record of a stegosaur. However, stegosaurs may have continued into the Maastrichtian (Lameta Formation) of western India as indicated by a pes print of Deltapodussp., a stegosaurian ichnotaxon.

Keywords

deltapodusdravidosaurusfootprintsindiabonesstegosauriadinosauriaupper cretaceousornithischia