Virtual reality at the NHM Trilobites are extinct arthropods from the Palaeozoic Era, that lived in prehistoric oceans between 540 to 245 million years ago. Their closest living relative is the horseshoe crab. Bryozoans are colonies made from many individual microscopic animals that are common in the seas both today and in the past.
Trilobites are the earliest arthropods and are the first known fossils with eyes.
Their hard outside skeleton, or exoskeleton, is divided into 3 lobes lengthways - hence the name. Their legs, which are rarely preserved, lay underneath. Many trilobites were capable of rolling up in a ball, probably for protection. Like all arthropods the hard outer skeleton meant that trilobites periodically moulted in order to grow bigger. The two trilobites shown here are from a famous British fossil locality, the Much Wenlock Limestone Formation, Dudley in the West Midlands.