mosasaurid
/ˌməʊsəˈsɔːrɪd/Palaeontology
noun
A reptile of the extinct family Mosasauridae; a mosasaur.
Origin
Late 19th century; earliest use found in James Dana (1813–1895), geologist, zoologist, and teacher. From mosasaur + -id, after scientific Latin Mosasauridae, family name from Mosasaurus + -idae.