An enigmatic (Synapsid?) tooth from the Early Cretaceous of New South Wales, Australia

Abstract

ABSTRACT Largely fragmentary fossils from sites in New South Wales, Victoria, and Queensland, Australia document terrestrial and marine vertebrate faunas of Aptian–Albian age. The natural cast of a large tooth from the Griman Creek Formation, Lightning Ridge, New South Wales, records the presence of a hitherto unknown member of the fauna. Although reference to one of the groups of crocodyliforms that evolved complex, mammal-like postcanine teeth cannot be excluded, the fossil more likely represents a species of synapsid. In some respects it is similar to lower postcanines of traversodontids. Greater morphological similarities to upper molars of dryolestids make reference of this tooth to this group more likely. Current Mesozoic Laurasian and Gondwanan fossil records include mammals with cheek teeth of similar large size.