Xenacanthus, a prehistoric shark from the Devonian and Triassic Period.

ANAL FINS • ANIMAL THEMES • ANIMAL • AQUATIC • ARTWORK • BIZARRE • CARNIVORE • CARTILAGINOUS FISH • CAUDAL FINS • CHONDRICHTHYES • COLOR IMAGE • COLOUR IMAGE • COPY SPACE • CREATURE • CUTOUT • DEVONIAN • DIGITALLY GENERATED IMAGE • DORSAL FINS • ELASMOBRANCH • EVOLUTION • EXTINCT • FIN • FISH • FLIPPER • FULL LENGTH • GIANT • GIGANTIC • HORIZONTAL • ILLUSTRATION • ILLUSTRATIONS • LARGE • LATERAL VIEW • LONG • MONSTER • MORPHOLOGY • NO PEOPLE • ONE ANIMAL • ORTHACANTHUS • OSTEICHTHY • OSTEICHTHYES • PALAEONTOLOGY • PALAEOZOOLOGY • PALEOBIOLOGY • PALEONTOLOGY • PALEOZOIC ERA • PALEOZOOLOGY • PAST • POWERFUL • PREDATOR • PREHISTORIC ERA • PRIMEVAL • PRIMITIVE • PRIMORDIAL • SCIENCE • SCIENCE: EVOLUTION • SEA LIFE • SHARK • SIDE VIEW • SLENDER • SPECIES • SPINE • TRIASSIC • UGLINESS • VERTEBRATE • WHITE BACKGROUND • WILDLIFE • WITHOUT PEOPLE • XENACANTHUS • ZOOLOGY