Cetiosaurus

Cetiosaurus oxoniensis

Cetiosaurus and sauros/σαυρος meaning 'lizard'), is a genus of herbivorous sauropod dinosaur from the Middle Jurassic Period, living about 171 to 165 million years ago during the Bajocian and Bathonian ages in what is now Britain and probably France. Cetiosaurus was named in 1842, making it 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