Pahasapasaurus haasi

Pahasapasaurus is an extinct genus of polycotylid plesiosaurs from Late Cretaceous rocks of the United States. Distinctive features of the taxon include elongate epipodial bones and the nature of the palate bones. The genus contains two species; type species, Pahasapasaurus haasi, was named in 2007 based on remains from the late Cenomanian-aged Greenhorn Limestone of South Dakota, In 2025, a second species was named, Pahasapasaurus gillettei, based on a complete skull and partial skeleton from the early Turonian-aged Tropic Shale of Utah.