Kolihapeltis rabatensis Trilobites Order Corynexochida, Family Styginidae Geological Time: Middle Devonian Size mm = 1 inch): Trilobite is 75 mm long (curve measure), 48 mm across (with spines). Matrix: 70 mm by 80 mm Fossil Site: Aatchana, Morocco
Helicoprion is a long-lived genus of extinct, eugeneodontid holocephalid fish. Almost all fossil specimens are of spirally arranged clusters of the individuals' teeth, called "tooth whorls." This fossilized jaw shows the spiral dentures.