Calymene Trilobite 521 million years old, Morocco
Trilobite Species: Calymene measurement: 3 x 1 7/8
520 million years old. Morocco
Trilobites were a very diverse group of extinct marine arthropods. They first appeared in the fossil record in the Early Cambrian (521 million years ago) and went extinct during the Permian mass extinction (250 million years ago). They were one of the most successful of the early animals on our planet with over 25k described species, filling nearly every evolutionary niche. Due in large part to a hard exoskeleton (shell), they left a excellent fossil record.
Trilobites were an exclusively marine group of arthropods that appeared in the Cambrian Period and persisted throughout the Paleozoic, eventually becoming extinct in the Permian Period. Most were small, bottom-dwelling organisms that fed on organic matter in sediment on the sea bottom. The body is divided in three segments: head (cephalon), middle (thorax), and tail (pygidium).