Polycotylidae

Polycotylids Temporal range: Ma PreꞒ Ꞓ O S D C P T J K Pg N
Martinectes in the Rocky Mountain Dinosaur Resource Center
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Superorder:	†Sauropterygia
Order:	†Plesiosauria
Clade:	†Leptocleidia
Family:	†Polycotylidae Williston, 1909
Genera
†Edgarosaurus †Georgiasaurus †Manemergus †Piratosaurus? †Rarosaurus †Occultonectia[1] †Plesiopleurodon †Sulcusuchus †Palmulasaurinae †Pahasapasaurus †Palmulasaurus †Polycotylinae †Eopolycotylus †Mauriciosaurus †Polycotylus †Scalamagnus †Serpentisuchops †Thililua? †Trinacromerum †Dolichorhynchia[2] †Dolichorhynchops †Martinectes †Unktaheela

Polycotylidae is a family of plesiosaurs from the Cretaceous, a sister group to Leptocleididae. Polycotylids first appeared during the Albian stage of the Early Cretaceous, before becoming abundant and widespread during the early Late Cretaceous. Several species survived into the final stage of the Cretaceous, the Maastrichtian.^[3]

With their short necks and large elongated heads, they resemble the

Cladogram after Albright, Gillette and Titus (2007).^[5]

Cladogram after Ketchum and Benson (2010).^[7]

Below is a cladogram of polycotylid relationships from Ketchum & Benson, 2011.^[8]

References