Theropod tooth assemblages from the Late Cretaceous Maevarano Formation and the possible presence of dromaeosaurids in Madagascar

Over 180 isolated theropod teeth recovered from the Maevarano Formation (Campanian?-Maastrichtian) of the Mahajanga Basin were studied in order to document theropod diversity in the Malagasy insular setting. Tooth morphology and characteristics of the Maevarano teeth were compared to those of known theropod teeth for identification, including the Malagasy non-avian theropods Majungatholus atopus and Masiakasaurus knopfleri. Tooth and denticle morphologies permit the recognition of five tooth morphotypes: three are referable to Majungatholus atopus and one to Masiakasaurus knopfleri. Statistical analyses reveal that the fifth morphotype is similar to dromaeosaurid teeth, suggesting that a yet unknown theropod taxon inhabited Madagascar during the Late Cretaceous. This morphotype support the theory that dromaeosaurids were present throughout Pangea before the break-up of the supercontinent during the Late Jurassic and had colonized Madagascar before its separation from Africa during the Early Cretaceous.