Endothiodon (Therapsida, Anomodontia) specimens from the middle/late permian of the Metangula Graben (Niassa Province, Mozambique) increase complexity to the taxonomy of the genus

Abstract Endothiodon is amongst the most cosmopolitan, easily identified and bizarre genera from the middle/late Permian. Its complex and unique feeding system with continuous replacement waves of teeth and its cranial morphology make it stand out among dicynodonts. Our increased sample of Endothiodon specimens from the K5 Formation (Middle/Late Permian) of the Metangula Graben (Niassa, Mozambique) raises new interest in the evolutionary history and taxonomy of the genus. Here we describe the anatomy of 111 new Endothiodon specimens from Mozambique and identify the presence of multiple specimens of E. tolani in possible co-occurrence with E. bathystoma, pending a more refined stratigraphic placement of E. bathystoma morph specimens. The overwhelming majority of specimens collected in the Metangula Graben are ascribable to Endothiodon. This scenario raises multiple evolutionary hypotheses for the genus with significant taxonomic implications. Importantly, the Mozambican specimens shed new light into the patterns of variation, ontogeny and dimorphism of endothiodont characters and Endothiodon autapomorphies.