Omosaurus is a dubious genus of extinct crurotarsan reptile, possibly a phytosaur, from the Late Triassic (Carnian) of North Carolina.

[1] In the middle of the nineteenth century, geologist Professor Ebenezer Emmons discovered several reptilian teeth in the colliery of the Chatham company in North Carolina.

Leidy combined the teeth with some vertebrae and ribs; adding to them an osteoderm or scute found in the same strata by Professor Michael Tuomey, he named the whole Omosaurus perplexus.

[1] Leidy himself believed Omosaurus to be a marine reptile, probably a plesiosaur, suspecting the remains were referable to some already named genus.

[3] Today, Omosaurus is commonly listed as a nomen dubium, a possible member of the Phytosauria.