Craniofacial Morphology of <i>Vintana Sertichi</i> (Mammalia, Gondwanatheria) from the Late Cretaceous of Madagascar

<div><p>ABSTRACT</p><p>The Gondwanatheria are an enigmatic clade of Cretaceous and Paleogene mammals known from South America, Africa, Madagascar, India, and the Antarctic Peninsula. The eight valid species—each belonging to a monotypic genus and the first of which was described only 30 years ago—are represented almost exclusively by isolated teeth, in addition to fragmentary dentaries attributed to <i>Sudamerica</i>, <i>Gondwanatherium</i>, <i>Ferugliotherium</i>, and an unnamed taxon from Tanzania. No cranial (skull exclusive of lower jaw) or postcranial material has heretofore been assigned to the Gondwanatheria, a severe limitation that has precluded a comprehensive assessment of phylogenetic affinities. Here we describe, in detail, the first cranial specimen of a gondwanatherian mammal. This material consists of a complete and well-preserved cranium of the sudamericid <i>Vintana sertichi</i>, recovered from the Upper Cretaceous (Maastrichtian) Maevarano Formation in the Mahajanga Basin of northwestern Madagascar. Salient features of the cranium include elongate, scimitar-like jugal flanges, huge orbits, strong klinorhynchy, and a vaulted nuchal region. Micro-computed tomography greatly facilitated the delineation of sutures and the description of internal morphology. The cranial features of <i>Vintana</i> are compared with those of a broad range of synapsids, with particular concentration on other Mesozoic mammaliaforms. The cranium of <i>Vintana</i> exhibits a mosaic of extremely primitive and extremely derived features. It is the second largest known for a Mesozoic mammaliaform, superseded only by that of the eutriconodontan <i>Repenomamus giganticus</i> from the Early Cretaceous of China. <i>Vintana</i> is the largest known Late Cretaceous mammaliaform; it is also the largest known Mesozoic mammaliaform from Gondwana.</p><p>SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at</p></div>