What is a trillabite?

A trilobite is an extinct marine arthropod that belongs to the class Trilobita, which thrived during the Paleozoic Era, particularly from the Cambrian to the Permian periods. Characterized by their three-lobed body structure, trilobites had a hard exoskeleton and are often found as fossils in sedimentary rock. They were diverse in form and function, ranging from filter feeders to active predators, and are considered important index fossils for geological dating. Their extinction occurred around 252 million years ago during the Permian-Triassic extinction event.