Researchers have found an enormous new mosasaur from Morocco, named Thalassotitan atrox, which stuffed the apex predator area of interest. With huge jaws and enamel like these of killer whales, Thalassotitan hunted different marine reptiles — plesiosaurs, sea turtles, and different mosasaurs.
On the finish of the Cretaceous interval, 66 million years in the past, sea monsters actually existed. Whereas dinosaurs flourished on land, the seas had been dominated by the mosasaurs, large marine reptiles.
Mosasaurs weren’t dinosaurs, however huge marine lizards rising as much as 12 metres (40 toes) in size. They had been distant family of recent iguanas and monitor lizards.
Mosasaurs regarded like a Komodo dragon with flippers as a substitute of legs, and a shark-like tail fin. Mosasaurs turned bigger and extra specialised within the final 25 million years of the Cretaceous, taking niches as soon as stuffed by marine reptiles like plesiosaurs and ichthyosaurs. Some developed to eat small prey like fish and squid. Others crushed ammonites and clams. The brand new mosasaur, named Thalassotitan atrox, developed to prey on all the opposite marine reptiles.
The stays of the brand new species had been dug up in Morocco, about an hour exterior Casablanca. Right here, close to the tip of the Cretaceous, the Atlantic flooded northern Africa. Nutrient wealthy waters upwelling from the depths fed blooms of plankton. These fed small fish, feeding bigger fish, which fed mosasaurs and plesiosaurs — and so forth, with these marine reptiles turning into meals for the enormous, carnivorous Thalassotitan.
Thalassotitan, had an unlimited cranium measuring 1.4 metres (5 toes lengthy), and grew to just about 30 toes (9 metres) lengthy, the scale of a killer whale. Whereas most mosasaurs had lengthy jaws and slender enamel for catching fish, Thalassotitan had a brief, extensive muzzle and large, conical enamel like these of an orca. These let it seize and rip aside enormous prey. These variations counsel Thalassotitan was an apex predator, sitting on the prime of the meals chain. The large mosasaur occupied the identical ecological area of interest as at present’s killer whales and nice white sharks.
Thalassotitan’s enamel are sometimes damaged and worn, nonetheless consuming fish would not have produced this kind of tooth put on. As a substitute, this means that the enormous mosasaur attacked different marine reptiles, chipping, breaking, and grinding its enamel because it bit into their bones and tore them aside. Some enamel are so closely broken they’ve been nearly floor right down to the basis.
Fossilised stays of prey
Remarkably, doable stays of Thalassotitan’s victims have been found. Fossils from the identical beds present injury from acids, with enamel and bone eaten away. Fossils with this peculiar injury embody giant predatory fish, a sea turtle, a half-meter lengthy plesiosaur head, and jaws and skulls of not less than three completely different mosasaur species. They’d have been digested in Thalassotitan’s abdomen earlier than it spat out their bones.
“It is circumstantial proof,” stated Dr Nick Longrich, Senior Lecturer from the Milner Centre for Evolution on the College of Tub and lead creator on the research, printed in Cretaceous Analysis.
“We won’t say for sure which species of animal ate all these different mosasaurs. However now we have the bones of marine reptiles killed and eaten by a big predator.
“And in the identical location, we discover Thalassotitan, a species that matches the profile of the killer — it is a mosasaur specialised to prey on different marine reptiles. That is in all probability not a coincidence.”
Thalassotitan was a risk to the whole lot within the oceans — together with different Thalassotitan. The massive mosasaurs bear accidents sustained in violent fight with different mosasaurs, with accidents to their face and jaws sustained in fights. Different mosasaurs present related accidents, however in Thalassotitan these wounds had been exceptionally frequent, suggesting frequent, intense fights over feeding grounds or mates.
“Thalassotitan was a tremendous, terrifying animal,” stated Dr Nick Longrich, who led the research. “Think about a Komodo Dragon crossed with a fantastic white shark crossed with a T. rex crossed with a killer whale.”
The brand new mosasaur lived within the ultimate million years of the Age of Dinosaurs, a up to date of animals like T. rex and Triceratops. Together with latest discoveries of mosasaurs from Morocco, it means that mosasaurs weren’t in decline earlier than the asteroid impression that drove the Cretaceous mass extinction. As a substitute, they flourished.
Professor Nour-Eddine Jalil, a co-author on the paper from the Museum of Pure Historical past in Paris, stated: “The phosphate fossils of Morocco supply an unparalleled window on the paleobiodiversity on the finish of Cretaceous.
“They inform us how life was wealthy and diversified simply earlier than the tip of the ‘dinosaur period’, the place animals needed to specialise to have a spot of their ecosystems. Thalassotitan completes the image by taking over the position of the megapredator on the prime of the meals chain.”
“There’s a lot extra to be performed,” stated Longrich. “Morocco has one of many richest and most numerous marine faunas identified from the Cretaceous. We’re simply getting began understanding the range and the biology of the mosasaurs.”
Weblog by Nick Longrich: https://www.nicklongrich.com/weblog/thalassotitan-the-killer-mosasaur