Corosaurus

Corosaurus is an extinct genus of pistosauroid known from Wyoming of the United States.^[1][2] The holotype measured about 1.65 m (5.4 ft) long, while larger specimens would have belonged to individuals measuring more than 4 m (13 ft) long.^[3]

Corosaurus Temporal range: Early Triassic, 247.4–245 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Corosaurus (12) and other Early Triassic marine predators
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Superorder:	†Sauropterygia
Clade:	†Pistosauroidea
Family:	†Corosauridae Kuhn, 1961
Genus:	†Corosaurus Case, 1936
Species:	†C. alcovensis
Binomial name
†Corosaurus alcovensis Case, 1936

History of discovery

Corosaurus is known from the holotype UW 5485, a partial skeleton which includes the skull.^[1] Later, the referred specimens YPM 41030-41068, FMNH PR 135, FMNH PR 1368-1369, FMNH PR 242-246 and FMNH PR 1382-1383 were described by Glenn William Storrs in 1991. All specimens were collected in Jackson Canyon, Natrona County, from the Chugwater Group of the Alcova Limestone Formation, dating to the late Olenekian stage of the late Early Triassic, about 247.4-245 million years ago.^[4]

Etymology

Corosaurus was first named by Ermine Cowles Case in 1936 and the type species is Corosaurus alcovensis. The specific name is derived from the name of the Alcova Limestone Formation, in which the holotype was found.^[1]

Classification

Corosaurus was placed in its own family, Corosauridae, which named by Oskar Kuhn, in 1961.^[4] After a revision of the holotype and referred material of Corosaurus, Olivier Rieppel found Corosaurus to be the sister-taxon to a clade comprising Cymatosaurus, Pistosaurus and Plesiosauria.^[2]