Adopt a cuddly fossil friend today with Paleozoic Pals from the Paleontological Research Institution. The Paleozoic is the era before dinosaurs, during which animal life first diversified in the seas, and eventually came ashore to become land vertebrates. Great for fossil-lovers of all ages, this soft trilobite is 8" long and ready to snuggle up to you! Trilobites crawled along the bottom of shallow seas for around 300 million years, from the beginning of the Cambrian Period to the end of the Permian Period. The name "trilobite" means "three lobes." They were an ancient kind of arthropod, the group that includes insects, spiders, and crustaceans.