Sphenosuchus

Sphenosuchus ("wedge crocodile") is an extinct genus of crocodylomorph from the Early Jurassic Elliot Formation of South Africa, discovered and described early in the 20th century. The skull is preserved very well but other than elements of the forelimb and isolated parts of the hind limb, the Sphenosuchus material is incomplete. It was probably quadrupedal, but may have been a facultative biped.

Sphenosuchus was first thoroughly described in 1972 by the British palaeontologist Alick Walker, in a paper in the journal Nature. Walker suggested, based on detailed (but still preliminary at that time) studies of the skull of Sphenosuchus and modern birds, that crocodylomorphs and birds might share an immediate common ancestor. Walker recanted his hypothesis in 1985, but restated and elaborated on it (in essence 'de-recanting') in a monograph published in 1990, which provided the most comprehensive description and discussion of Sphenosuchus yet published.