Britain's oldest sauropod dinosaur has been identified from a fossil bone discovered on the North Yorkshire coast, experts have revealed.
Its veterbra was discovered after it fell from a cliff face onto a beach near Whitby.
Tests by University of Manchester scientists indicate it is about 176 million years old, dating from the Middle Jurassic period.
The fossil is to go on display at the Yorkshire Museum from 8 June.
Sauropods, often referred to as brontosaurs, included some of the largest plant-eating dinosaurs to have walked on Earth.
They had long necks and tails, small heads, a large body and walked on all fours. Some species, such as the Argentinosaurus, grew up to 115ft long and possibly weighed as much as 80 tonnes.
The museum said the fossil was "an extremely rare find" because Middle Jurassic rocks are only exposed in a few areas such as China and Argentina, where similarly aged dinosaur fossils originate.
Prof Phil Manning and his team used X-rays to study the fossil bone.
He said: "It was a splendid surprise to come face-to-face with a fossil vertebra from the Jurassic rocks of Yorkshire that was clearly from a sauropod dinosaur.
"This fossil offers the earliest 'body fossil' evidence for this important group of dinosaurs in the United Kingdom but it is impossible to define a new species based upon this single bone."
The team have nicknamed the dinosaur Alan, after the man who found the fossil.