Orthosuchus strombergi Nash, 1968

Nesbitt, Sterling J., 2011, The Early Evolution Of Archosaurs: Relationships And The Origin Of Major Clades, Bulletin of the American Museum of Natural History 2011 (352), pp. 1-292 : 42

Orthosuchus strombergi Nash, 1968

AGE: Early Jurassic ( Olsen and Galton, 1984).

OCCURRENCE: Upper Elliot Formation, Orange River Valley, Qacha’s Nek Providence, Lesotho ( Nash, 1975).

HOLOTYPE: SAM-K-409, complete skull and nearly complete skeleton missing the caudal region.

REFERRED MATERIAL: SAM-K-4639, skull and mandibles; BP/1/4770, articulated postcranium.

REMARKS: Orthosuchus was named for a nearly complete, three-dimensionally prepared skeleton from near the top of the upper Elliot Formation of Lesotho ( Nash, 1968, 1975). As mentioned by Clark (in Benton and Clark, 1988), the holotype is dorsoventrally crushed and, as a result, some characters discussed by Nash (1975) are the result of crushing. Between the holotype and the two referred specimens, most of the anatomy of Orthosuchus can be scored.

Orthosuchus was found as a crocodyliform more closely related to Protosuchus than to Crocodylus in all explicit phylogenies of basal crocodyliform relationships ( Benton and Clark, 1988; dataset of Pol et al., 2004, 2009). Clark (in Benton and Clark, 1988) listed the following character states that are shared with Protosuchus : ventrolateral contact of otoccipital with quadrate relatively broad ( Busbey and Gow, 1984); squamosal relatively thick; vomer transversely broad, not rodlike.

KEY REFERENCES: Nash, 1968, 1975; Benton and Clark, 1988.