Mega-Predator: Fossils Discovered of Giant Sea Monster That Ruled the Oceans 66 Million Years Ago
Paleontologists have discovered a huge new mosasaur from Morocco, named Thalassotitan atrox, which filled the apex predator niche. With massive jaws and teeth like those of killer whales, Thalassotitan hunted other marine reptiles — plesiosaurs, sea turtles, and other mosasaurs. ...
Mosasaurs weren’t actually dinosaurs, but enormous marine lizards growing up to 12 meters (40 feet) in length. They were distant relatives of modern iguanas and monitor lizards.
Mosasaurs looked like a Komodo dragon, except with flippers instead of legs, and a shark-like tail fin. Mosasaurs became larger and more specialized in the final 25 million years of the Cretaceous period, taking niches once filled by other marine reptiles like plesiosaurs and ichthyosaurs. Some evolved to eat small prey like fish and squid. Others crushed ammonites and clams. The new mosasaur, named Thalassotitan atrox, evolved to prey on all the other marine reptiles.
The remains of the new species were discovered in a dig in Morocco, about an hour outside Casablanca. Here, near the end of the Cretaceous, the Atlantic flooded northern Africa. Nutrient-rich waters upwelling from the depths fed blooms of plankton. Those fed small fish, feeding larger fish, which fed mosasaurs and plesiosaurs — and so on, with these marine reptiles becoming food for the gigantic, carnivorous Thalassotitan. ...
Thalassotitan had an enormous skull measuring 1.4 meters (5 feet) long, and grew to nearly 9 meters (30 feet) long, the size of a killer whale. Most mosasaurs had long jaws and slender teeth for catching fish, but Thalassotitan had a short, wide muzzle and massive, conical teeth like those of an orca. These let it seize and rip apart huge prey. These anatomical adaptations suggest Thalassotitan was an apex predator, sitting at the top of the food chain. Essentially, the giant mosasaur occupied the same ecological niche as today’s killer whales and great white sharks.
Thalassotitan’s teeth are often worn and broken. Eating fish wouldn’t have produced this sort of tooth wear. Instead, this suggests that the giant mosasaur attacked other marine reptiles, chipping, grinding, and breaking its teeth as it bit into their bones and tore them apart. Some teeth are so heavily damaged they have been almost ground down to the root. ...
Remarkably, possible remains of Thalassotitan’s victims have also been discovered. Fossils from the same beds show damage from acids, with teeth and bone eaten away. Fossils with this peculiar damage include large predatory fish, a sea turtle, a half-meter-long (1.6-foot-long) plesiosaur head, and jaws and skulls of at least three different mosasaur species. They would have been digested in Thalassotitan’s stomach before it spat out their bones. ...