'Sea Monsters' Were Real Millions of Years Ago. New Fossils Tell About Their Rise and Fall TC_Africa: Morocco
. We can't prove Thalassotitan ate them, but it fits the profile of the killer, and nothing else does, making it the prime suspect.
Thalassotitan, sitting at the top of the food chain, also tells a lot about ancient marine food chains, and how they evolved in the Cretaceous.The discovery of Thalassotitan tells us about marine ecosystems just before the asteroid hit 66 million years ago, ending the age of the dinosaurs. Thalassotitan was just one of a dozen mosasaur species living in the waters off of Morocco. Mosasaurs made up a fraction of all the thousands of species living in the oceans, but the fact that predators were so diverse implies that lower levels of the food chain were diverse too, for the oceans to be able to feed them all. This means that the marine ecosystem wasn't in decline before the asteroid hit.
Instead, mosasaurs and other animals - plesiosaurs, giant sea turtles, ammonites, countless species of fish, molluscs, sea urchins, crustaceans - flourished, then died out suddenly when the, launching dust and soot into the air, and blocking out the sun. Mosasaur extinction wasn't the predictable result of gradual environmental changes. It was the unpredictable result of a sudden catastrophe. Like a lightning strike from a clear blue sky, their end was swift, final, unpredictable.
But mosasaur evolution may also have started with a catastrophe. Curiously, the evolution of the giant carnivorous mosasaurs resembles that of another family of predators - the Tyrannosauridae. The giant T. rex evolved on land at about the same time that mosasaurs became top predators in the seas. Is that a coincidence? Maybe not.