trilobites

Trilobites were a diverse group of marine arthropods that thrived during the Paleozoic Era, which lasted from about 541 to 252 million years ago. They were the most dominant group of animals during the Cambrian Period, which marked the beginning of the Paleozoic Era. Trilobites were characterized by their distinctive three-lobed body structure, which gave them their name. The three lobes ran the length of the body, dividing it into a central axis and two lateral lobes.

Trilobites were highly diverse, with over 20,000 different species identified. They varied greatly in size, from a few millimeters to over 70 centimeters long. Some trilobites were covered in spines or bumps, which may have served as protection or camouflage. Others had large, complex eyes that allowed them to see in a wide range of directions.

Trilobites went extinct at the end of the Permian Period, 252 million years ago, during a mass extinction event that wiped out over 90% of all life on Earth. However, their fossils are abundant and widespread, making them one of the most recognizable and well-studied groups of extinct animals.