Platecarpus

Platecarpus ("Flat wrist") is an extinct genus of lizard belonging to the mosasaur family. It was about 4.30 meters (14 ft) long.

Like other mosasaurs, Platecarpus had a long, laterally flattened tail, steering flippers and deadly, tooth-lined jaws. It probably swam in a snake-like fashion. Platecarpus fed on fish, squid and ammonites.

Platecarpus was probably the most common genus of mosasaur in the Western Interior Sea during the deposition of the Smoky Hill Chalk in Kansas, and Platecarpus ictericus is the species that is found most often. There is some controversy regarding the description of the genus Platecarpus since it includes some diverse, and possibly unrelated forms. They were medium sized animals, reaching about 7 meters (21 feet) in length. Compared to the tylosaurs, plioplatecarpine mosasaurs had much less robust teeth, suggesting that they fed on smaller (or softer) prey such as small fish and squid. The platecarpine mosasaurs had evolved into the very specialized plioplatecarpine group by the end of the Cretaceous. See Williston 1898 for drawings of the skull of Platecarpus ictericus.