A second Cretaceous mammalian specimen from Lightning Ridge, N.S.W., Australia

Abstract

The recognition of a second mammalian specimen regarded as coming from the Early Cretaceous Griman Creek Formation at Lightning Ridge, N.S.W., Australia corroborates the provenance of the holotype of Steropodon galmani Archer et al. 1985. The new specimen is an edentulous maxilla with multiple-rooted cheekteeth. Orientation of the roots is unlike that of tritylodontid therapsids, the only group of vertebrates other than mammals with multiple-rooted teeth.