Massive sea monster
This is a superbly-preserved plesiosaur vertebra (backbone) complete with the neural arch. This would have been from a BIG animal, at least seven or eight metres in length. There is a hole between the round vertebra and the neural arch through which the spinal cord ran. The large extensions on the neural arch are attachment points for muscles that enabled the animal to flex its long neck and tail.
Find out more on the reptiles page.