Shark Tooth - Sharks appeared over 300 million years ago. Their skeletons are made of catilage, which is rarely fossilised, but their teeth are very durable.
Crinoid - Crinoids are marine animals that live in shallow waters and in depths of up to 6000 metres. They date back to 488 million years ago.
Gastropod - Gastropods are more commonly known as snails and slugs. There are at least 15,000 different prehistoric species.
Ammonite - Ammonites thrived in the seas during the time of dinosaurs and ranged in size from a 10c to a tractor tyre.
Brachiopod - Brachiopods are marine animals that have shells on their upper and lower surfaces, that are hinged together at the rear.