Andegavia simplex, Devonian trilobite fossil. Trilobites were arthropods that mostly fed as they crawled on the seabed. They lived between 500 and 300 million years ago and are now extinct. This specimen dates from the Middle Devonian, and was found in Eifelian stage rocks near Hamar Laghdad, Morocco. A rather bizarre trilobite, it evolved into a ball of spines and almost certainly had a free-floating planktonic lifestyle. It has two large holochroal eyes. This specimen measures 5.5 centimetres across.