THE PREMAXILLA OF MAJUNGASAURUS (DINOSAURIA, THEROPODA), WITH IMPLICATIONS FOR GONDWANAN PALEOBIOGEOGRAPHY

In the austral winter of 1993, a joint SUNY-Stony Brook/Universite d'A ntananarivo expedition recovered numerous specimens of fossil vertebra tes from Upper Cretaceous terrestrial deposits in the Mahajanga Basin, northwestern Madagascar (Fig. 1; Krause and Hartman, 1996). Among the se was a nearly complete, exquisitely preserved premaxilla of the poor ly known large theropod, Majungasaurus crenatissimus. This element, th e first known cranial remains of M. crenatissimus, possesses derived m orphology supporting placement of the taxon within the ceratosaurian c lade Abelisauridae. It also shares several synapomorphies with the pre maxilla of Indosuchus raptorius, a large theropod from the Late Cretac eous of India. Other than overall size, there are no significant diffe rences in the premaxillae of these two taxa, supporting contentions th at: 1) Majungasaurus and Indosuchus are sister taxa within Abelisaurid ae; and 2) Madagascar and the Indian subcontinent remained part of the same biogeographic province into the Late Cretaceous.