Mastodonsaurus Jaeger, 1828

Genus Mastodonsaurus Jaeger, 1828

Type species.

Mastodonsaurus giganteus Jaeger, 1828 .

Diagnosis.

Autapomorphies (Figs 2 View Figure 2 – 6 View Figure 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.