Classification

Sauropterygia > Eosauropterygia > Eusauropterygia > Plesiosauria > Plesiosauroidea > Euplesiosauria > Cryptocleidoidea > Polycotylidae

Discussion

Polycotylids were believed to be pliosaurs because of their short necks and large heads, but a number of detailed analyses have revealed that they are in fact plesiosauroids, more closely related to the long necked elasmosaurids and cryptoclidids, than to true pliosaurs. They share a number of features including the elongate rostrum and short postorbital region. They had a worldwide distribution in the Cretaceous Period.

Genera

Dolichorhynchops

Edgarosaurus

Polycotylus

Thililua

Trinacromerum