Orthacanthus was a freshwater shark that thrived in the Devonian Period.

AGGRESSION • ANIMAL THEMES • ANIMAL • ANIMALS IN THE WILD • APEX PREDATOR • AQUATIC • ARTWORK • BAYOU • BIZARRE • CARBONIFEROUS PERIOD • CARBONIFEROUS • CARNIVORE • CARTILAGINOUS FISH • CHONDRICHTHYES • COLOR IMAGE • COLOUR IMAGE • CREATURE • DAY • DEVONIAN • DIGITALLY GENERATED IMAGE • ELASMOBRANCH • ENVIRONMENT • EVOLUTION • EXTINCT • FIERCE • FIN • FISH • FIVE ANIMALS • FLEET • FRESH WATER • FRESHWATER • FULL LENGTH • FULL-LENGTH • GROUP • HORIZONTAL • ICHTHYOLOGY • ILLUSTRATION • ILLUSTRATIONS • LAKE • LARGE • LATERAL VIEW • LONG • MARINE BIOLOGY • MARINE • MORPHOLOGY • MOUTH OPEN • NATURAL HISTORY • NATURAL SCIENCES • NATURE STUDY • NATURE • NAVY • NO PEOPLE • OCEAN FLOOR • OCEAN • OPEN MOUTH • OPEN-MOUTHED • ORTHACANTHUS SHARK • ORTHACANTHUS • OSTEICHTHY • OSTEICHTHYES • OUTDOOR • OUTDOORS • OUTSIDE • PALAEONTOLOGY • PALAEOZOOLOGY • PALEOART • PALEOBIOLOGY • PALEOICHTHYOLOGY • PALEONTOLOGY • PALEOZOIC ERA • PALEOZOOLOGY • PAST • PLANT • POWERFUL • PREDATOR • PREHISTORIC ERA • PRIMEVAL • PRIMITIVE • RIVER • SCHOOL OF FISH • SCIENCE • SCIENCE: EVOLUTION • SEA LIFE • SEA • SEAS • SHARK • SIDE VIEW • SLENDER • SPECIES • SWAMP • SWIMMING • TOGETHERNESS • TROPICAL CLIMATE • UGLINESS • UNDERSEA • UNDERWATER • VERTEBRATE • WATER • WILDERNESS • WILDLIFE • WITHOUT PEOPLE • XENACANTHUS • ZOOLOGY