in 1921. According to Ben Creisler, the prefix does not come from the Latin ante, but would refer to a Giant of the Greek mythology, Antaios, which once Latinized give Antaeus or more rarely Anteus. The type specimen of Anteosaurus is an incomplete skull that Watson had initially classified in the genus Titanosuchus, named after the Titans of the Greek mythology. Once this specimen recognized as belonging to a different genus, the name dedicated to Antaeus established another connection with a giant of Greek mythology. Description Size Anteosaurus is one of the largest known carnivorous non-mammalian synapsid and anteosaurid, estimated to have reached more than in length, and a body mass of about . Juvenile specimen BP/1/7074 has an estimated body mass of about , showing extreme disparity in size with adult Anteosaurus. Skull The skull of Anteosaurus is large and massive, measuring between in the largest specimens (TM265 and SAM-PK-11293), with an heavily pachyostosed skull roof showing a frontal boss more of less developed. The main features of the skull are the massively pachyostosed postfrontals that form strong horn-like bosses projected laterally. A boss, characteristically oval in shape, is also present on the angular bone of the lower jaw. The morphology of this angular boss is different between each anteosaurids species. In Anteosaurus the boss is oval in shape, roughly the same thickness throughout its length, with blunt anterior and posterior edges. Some individuals may have also a jugal boss more of less pronounced. Like other anteosaurids, the postorbital bar is strongly curved anteroventrally in such way that the temporal fenestra undercuts the orbit. An additional typical character of anteosaurs is the premaxilla oriented upwards at an angle of about 30 to 35° with respect to the ventral edge of the maxilla. However, unlike most anteosaurs in which the ventral margin of the premaxilla is directed upwards in a straight line, in Anteosaurus the anterior end of the premaxilla is curved ventrally, producing a concave alveolar border of the region preceding the canines. The skull shows also a concave dorsal snout profile. On the top of the skull, the pineal boss is exclusively formed by the parietals as is the case in other anteosaurines (and in more basal anteosaurs such as Archaeosyodon and Sinophoneus) while this boss is made up of both frontals and parietals in the other anteosaur subgroup, the syodontines. Contrary to what is observed in the