Cetiosauriscus

Cetiosauriscus is a genus of sauropod dinosaur that lived between 166 and 164 million years ago during the Callovian in what is now England. The only known fossil includes most of the rear half of a skeleton as well as a hindlimb. A herbivore, it had a moderately long tail, and longer forelimbs, making them as long as its hindlimbs.

About Cetiosauriscus in brief

Summary CetiosauriscusCetiosauriscus is a genus of sauropod dinosaur that lived between 166 and 164 million years ago during the Callovian in what is now England. The only known fossil includes most of the rear half of a skeleton as well as a hindlimb. A herbivore, it had a moderately long tail, and longer forelimbs, making them as long as its hindlimbs. The type species of Cetiosaurus has changed throughout history because of incomplete remains and the taxon’s significance, and many aspects of its anatomy and relationships are still uncertain. The more complete Middle Jurassic species C. oxoniensis named by geologist John Phillips in 1871 became the type species. An additional species, C. hulkei, was named in 1870 by palaeontologist Harry Seeley for a vertebraee from the Early Cretaceous Wessex Formation, younger than the existing species. C. leedsii, from the Late Jurassic, showed similarities to the older Cetosaurus oxonienis, but as younger as Oulkeas hulkesi, it is considered to be more closely related to Cetosaurus. The fossil was found in the marine deposits of the Oxford Clay Formation alongside many different invertebrate groups, marine ichthyosaurs, plesiosaurs and crocodylians, a single pterosaur, and various dinosaurs: the ankylosaur Sarcolestes, the stegosaurs Lexovisaurus and Loricatosaurus, the ornithopod Callovosaurus, and some unnamed taxa.

The theropods Eustreptospondylus and Metriacanthosaurus are known from the formation, although probably not from the same level as CetariosauriscUS. Cetioosaurus stewarti became the oldest confirmed diplodocid until a phylogenetic analysis published in 2003 instead found the species to belong to Mamenchisauridae, and followed by studies in 2005 and 2015 that found it outside Neosauropoda, while not a mamenchisaurusaurid proper. The species was named by Alan Charig in 1980 because of the lack of comparable material to the type of C. leedsi; this species is now called CetIOsaurus stewarto. It is one of the first sauropods to be named, and one with a complicated history due to many unfounded referrals of species and specimens, involving almost all English sauro pod specimens. It has been estimated as about 15 m long and between 4 and 10 t in weight. It was originally named to include C. medius, C brevis, C  brachyurus and C. longus, which span from the Middle Jurassic to the EarlyCretaceous of various localities across England. It had a dubious or indeterminate species called C. glymptonensis.