New megaraptorid (Dinosauria: Theropoda) remains from the Lower Cretaceous Eumeralla Formation of Cape Otway, Victoria, Australia

Abstract

<p>Megaraptorid theropods thrived in South America and Australia during the mid-Cretaceous. Their Australian record is currently limited to the upper Barremian-lower Aptian upper Strzelecki Group and the upper Aptian-lower Albian Eumeralla Formation of Victoria, the Cenomanian Griman Creek Formation of New South Wales, and the Cenomanian- lowermost Turonian Winton Formation of Queensland. The latter has produced <i>Australovenator wintonensis</i>, the stratigraphically youngest and most complete Australian megaraptorid. The Eric the Red West (ETRW) site on Cape Otway, Victoria (Eumeralla Formation; lower Albian), has yielded two teeth, two manual unguals, and a right astragalus that are almost identical to the corresponding elements in <i>Australovenator</i>. Herein, we classify these as Megaraptoridae cf. <i>Australovenator wintonensis</i>. We also reappraise the 'spinosaurid' cervical vertebra from ETRW and suggest that it pertains to Megaraptoridae. Three other theropod elements from ETRW-a cervical rib (preserving a bite mark), a caudal vertebra, and a non-ungual manual phalanx-are also described, although it is not possible to determine their phylogenetic position more precisely than Tetanurae (non-Maniraptoriformes). All elements were found in a fluvial deposit, associated with isolated bones of other theropods, ornithopods, and turtles, amongst others; consequently, no two can be unequivocally assigned to the same theropod individual. The new specimens from ETRW demonstrate that a megaraptorid theropod morphologically similar to <i>Australovenator</i> lived during the late Early Cretaceous in Victoria, at a higher paleolatitude than its northern counterpart. Moreover, they attest to the success of megaraptorids in late Barremian-early Turonian faunas throughout eastern Australia.</p>