Mastodonsaurus Jaeger 1828

GenusMastodonsaurusJaeger, 1828 Type species. Mastodonsaurus giganteus Jaeger, 1828. Diagnosis. Autapomorphies (Figs 2 – 6): (1) Premaxilla with openings for symphyseal tusks, set well anterior to naris; (2) orbits large, reaching one-fifth of skull length; (3) jugal slender lateral to orbit; (4) parietal elongated anterior to pineal foramen; (5) lateral line sulci very wide; (6) epipterygoid massive and complex, with six distinct processes (footplate, pr. anterior, pr. dorsalis, pr. sphenethmoidalis, pr. basalis, pr. posterior). Characters shared with other capitosaurs: (a) interclavicle with elongated anterior process; (b) elongate postglenoid area; (c) tall hamate process. Comment. Character (1) is shared with C. naraserluki and C. mordax (Fraas 1913; Marzola et al. 2017) and also occurs in one specimen of C. robustus (Schoch and Moreno 2024). However, Mastodonsaurus differs from all these in having a more elongated premaxilla anterior to the naris and a more lateral and posterior emplacement of the opening with respect to the anterior snout margin (Schoch and Moreno 2024). Character (4) is shared with metoposaurids, but no other taxon with Capitosauroidea.