Platecarpus was a medium-sized mosasaur with long, narrow jaws lined with sharp, pointy teeth. This marine lizard grew to 24 feet (7 meters) in length and roamed the shallow seas of the Late Cretaceous in search of small fish and squid. Platecarpus was more selective in its diet than its larger and more ferocious relative Tylosaurus, a deadly hunter with eyes for anything that moved.
While not the biggest mosasaur, Platecarpus was one of the most abundant; its fossils have been found in ancient seabeds in North America, Europe, and Africa.
As with all mosasaurs, a long and muscular, vertically flattened tail powered Platecarpus through the water in snakelike fashion while flipper-like limbs provided the steering. Some fossilized specimens have thick eardrums, an adaptation that may have allowed the sea monster to chase fish into deep waters.