During the Middle Triassic, 245 MYA, estuarine mud and seabed sand were home to a surfeit of small animals. A dinosaur arose to take advantage of this potential feast.
Atopodentatus grew to 3 meters long. Not as well-adapted to life at sea as aquatic icthyosaurs, this quadruped had paddle feet but could also walk on land.
Atopodentatus‘ dentition was unlike any other animal ever. Its head was shovel-shaped, armed with an arc of over 175 tiny, needle teeth that fused to the sides of the jaw rather than sitting in sockets. Inwardly, the teeth were bladelike, arranged like a comb. Most of the teeth in the upper jaw faced each other, in a split running between the 2 halves of the upper jaw.
Atopodentatus was a filter feeder: it stuck its snout in the mud, took a mouthful of sediment, and sifted for puny prey, such as worms. Squeezing the sand through its teeth let Atopodentatus comb through prey like a baleen whale traps krill.