Morphology of a specimen of *Supersaurus* (Dinosauria, Sauropoda) from the Morrison Formation of Wyoming, and a re-evaluation of diplodocid phylogeny

Abstract

A new specimen of Supersaurus vivianae is described, providing additional information about the osteology of Supersaurus. The single Supersaurus individual that the WDC quarry produced allows a reexamination of elements referred to Supersaurus from the Dry Mesa quarry. The osteology supports maintaining the generic distinction of Supersaurus. Phylogenetic evaluation finds a monophyletic Apatosaurinae containing [Apatosaurus + Supersaurus] + Suuwassea, and a monophyletic Diplodocinae containing [Diplodocus + Seismosaurus] + Barosaurus, although the generic distinction of Seismosaurus is not supported in the current analysis.