Eryopidae Cope 1882

Eryopidae Cope, 1882 Diagnosis. Synapomorphies (from Werneburg et al. 2023, after Sawin 1941; Romer 1947; Boy 1990; Milner 1989, 1990; Werneburg and Steyer 1999; Schoch and Hampe 2004; Werneburg 2007; Werneburg and Berman 2012; Schoch and Milner 2014): (1) Enlarged choana medially wide; (2) Ectopterygoid, palatine and vomer only with two or three fangs (without subsequent smaller teeth); (3) Lacrimal reaches anteriorly to the naris or septomaxilla; (4) Enlarged posterior width of skull (pS w / S l = 0.92–1.10; compare Fig. 2); (5) Posterior part of the cultriform process widened (partly); (6) Interclavicle of adults proportionally small and broadly-ovate in outline; (7) Ilium with vertically directed dorsal process, which is anteroposteriorly widened dorsally. All three species to be revised, Clamorosaurus nocturnus, C. borealis and Syndyodosuchus tetricus, fulfill the first four criteria of the family diagnosis. The fifth diagnostic feature is not present in all eryopid genera, only in Eryops and Onchiodon. The sixth and seventh diagnostic features concern the interclavicle and ilium, which have not been recorded in all three species. In this respect, all these species can be assigned to the family Eryopidae.