How many bones make a back?
This is a large ichthyosaur vertebra or backbone. The preservation, the colour and texture indicate that this is from the Lower Jurassic rocks, almost certainly from around Lyme Regis. Vertebrae are much more common than paddle bones or skulls for a very simple and obvious reason. Each animal had about 180 vertebrae making up their backbone or vertebral column, but only one head and four paddles!
Find out more on the reptiles pages.