Sphenosuchus acutus Haughton, 1915

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 : 40-41

Sphenosuchus acutus Haughton, 1915

(fig. 12A–B)

AGE: Early Jurassic ( Olsen and Galton,

1984).

OCCURRENCE: Upper Elliot Formation, South Africa.

HOLOTYPE: SAM 3014, nearly complete skull, cervical vertebrae, pectoral girdle, humeri, tibia, metatarsals.

REMARKS: Sphenosuchus , originally described by Haughton (1915), was studied by Walker for over 30 years. From the beginning, Sphenosuchus was considered a close relative of crocodylians. In an unprecedented and unparalleled study of a basal archosaur, Walker (1990) disassembled, and in astonishing detail, prepared the entire skull. He revealed particulars of the braincase that united Sphenosuchus with crocodyliforms that were later used by Gower and Walker (2002) and Gower (2002) in a braincase study of basal archosaurs. The divergent postcranium of Sphenosuchus formed the basis of an argument for a long-limbed clade, Sphenosuchia , at the base of Crocodylomorpha ( Sereno and Wild, 1992; Wu and Chatterjee, 1993).

KEY REFERENCES: Haughton 1915; Walk- er, 1970, 1990; Clark et al., 2000.