Sharks and shark-like fish (Chondrichthyes) are found from Upper Ordovician through Cretaceous sediments in Flood deposits, as well as in many post-Flood sediments. Cartilage does not preserve as well as bone, so teeth are most commonly discovered. Less common are spines, vertebrae, and denticles.
Elasmobranchs before the Flood were highly diverse in size, shape, and habit. Very strange sharks like Edestus had jaws positioned like scissors, while Helicoprion had a whorl of teeth on its lower jaw. Listracanthus had long feather-like denticles on its eel-like body. Stethacanthus had an anvil-shaped dorsal fin covered on the top with spiny bristles. Most such specialized sharks did not survive the Flood.
