Osteology of Simosaurus gaillardoti and the relationships of stem- group Sauropterygia

Abstract

Simosaurus gaillardoti H. v. Meyer, 1842, is recognized as the only species of its genus. An amended diagnosis of the genus is given here, Simosaurus mougeoti H. v. Meyer, 1842, is a lower jaw of Nothosaurus; Simosaurus guilielmi H. v. Meyer, 1947-1855, is a junior synonym of Simosaurus gaillardoti. The skeletal morphology of Simosaurus is redescribed in detail and compared to that of other stem-group (non plesio- and pliosaur) Sauropterygia. Ninety-four skeletal characters are defined and used in a phylogenetic analysis. Functional morphological correlates of the skeleton suggest that Simosaurus was capable of sustained swimming in the shallow epicontinental sea in pursuit of prey such as "holostean'-grade fishes and, perhaps, ammonites. -from Author