Polycotylus was a plesiosaur, a type of marine reptile. It was not a dinosaur, though it coexisted with many dinosaurs. The first Polycotylus fossil was discovered in 1869.
All the Polycotylus illustrations below were collected from the internet. Enjoy and explore:
- E. D. Cope. 1869. Synopsis of the Extinct Batrachia, Reptilia and Aves of North America. Part I. Transactions of the American Philosophical Society, New Series 14:1-104
- G. W. Storrs. 1999. An examination of Plesiosauria (Diapsida: Sauropterygia) from the Niobrara Chalk (Upper Cretaceous) of Central North America. Paleontological Contributions of the University of Kansas 11:1-15
- S. W. Williston. 1905. A new armored dinosaur from the Upper Cretaceous of Wyoming. Science 22(564):503