A new sphenodontian (Lepidosauria: Rhynchocephalia) from the McCoy Brook Formation (Lower Jurassic) of Nova Scotia, Canada

ABSTRACT

A new sphenodontian lepidosaur referable to Clevosaurus Swinton, 1939, C. bairdi, is described from the McCoy Brook Formation (Lower Jurassic: Hettangian) of Nova Scotia, Canada. It is most closely related to C. mcgilli Wu, 1994 from the Dark Red Beds of the Lower Lufeng Formation (Lower Jurassic) of Yunnan, China, and differs from the latter mainly in the absence of the hourglass-shaped constriction of the parietals, the shape of the suborbital fenestra, and in features of the marginal dentition. The new taxon is of considerable interest because it represents the first record of Clevosaurus from North America. Like many other early Mesozoic continental tetrapods, Clevosaurus had an apparently Pangaean geographic distribution.