Polycotylidae

Polycotylidae is a family of plesiosaurs from the Cretaceous, a sister group to Leptocleididae.

Polycotylids Temporal range: Early - Late Cretaceous, 103–66 Ma PreЄ Є O S D C P T J K Pg N
Dolichorhynchops bonneri in the Rocky Mountain Dinosaur Resource Center
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Superorder:	†Sauropterygia
Order:	†Plesiosauria
Clade:	†Leptocleidia
Family:	†Polycotylidae Williston, 1909
Genera
†Dolichorhynchops †Edgarosaurus †Eopolycotylus †Georgiasaurus †Manemergus †Mauriciosaurus †Pahasapasaurus †Palmulasaurus †Plesiopleurodon †Polycotylus †Rarosaurus †Sulcusuchus †Thililua? †Trinacromerum †Umoonasaurus?

With their short necks and large elongated heads, they resemble the pliosaurs, but closer phylogenetic studies indicate that they share many common features with the Plesiosauridae and Elasmosauridae. They have been found worldwide, with specimens reported from New Zealand, Australia, Japan, Morocco, the US, Canada, Eastern Europe, and South America.[1]