What is "clidastes"

Clidastes \Cli*das"tes\, n. [NL., prob. from Gr. klei`s key.] (Paleon.) A genus of extinct marine reptiles, allied to the Mosasaurus. See Illust. in Appendix.

Clidastes is a genus of extinct mosasaurine lizard that lived during the Late Cretaceous Period from 99.6 million to 65.5 million years ago in North America, and Europe. Clidastes was an agile swimmer that probably swam by undulating its body, and preyed on cephalopods, fish and other small vertebrates in shallow water.