Cetiosaurus

Cetiosaurus Temporal range: Bajocian-Bathonian ~170–166 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Mounted skeleton, Leicester Museum & Art Gallery
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	Saurischia
Clade:	†Sauropodomorpha
Clade:	†Sauropoda
Family:	†Cetiosauridae
Subfamily:	†Cetiosaurinae Lydekker, 1888
Genus:	†Cetiosaurus Owen, 1841
Species:	†C. oxoniensis
Binomial name
†Cetiosaurus oxoniensis Phillips, 1871

Cetiosaurus (/ˌsiːtioʊˈsɔːrəs, ˌsiːʃi-/)^[1] meaning 'whale lizard', from the Greek keteios/κήτειος meaning 'sea monster' (later, 'whale') and sauros/σαυρος meaning 'lizard', is a genus of herbivorous sauropod dinosaur from the Middle Jurassic Period, living about 168 million years ago in what is now Britain.

Cetiosaurus was in 1842 the first sauropod from which bones were described and is the most complete sauropod found in England. It was so named because its describer, Sir Richard Owen, supposed it was a marine creature, initially an extremely large crocodile, and did not recognise it for a land-dwelling dinosaur. Because of the early description many species would be named in the genus, eventually eighteen of them. Most of these have now been placed in other genera or are understood to be dubious names, based on poor fossil material. The last is true also of the original type species, Cetiosaurus medius, and so C. oxoniensis was officially made the new type species in 2014. C. oxoniensis is based on three more or less complete specimens, discovered from 1868 onwards. Together they contain most of the bones, with the exception of the skull.

Cetiosaurus oxoniensis was a quadrupedal, long-necked, small-headed herbivore. It had a shorter tail and neck than most sauropods. The forelimbs on the other hand, were relatively long. C. oxoniensis is estimated to have been about 16–18 metres (52–59 ft) long and to have weighed roughly 11 tonnes (12 short tons).