Before an asteroid changed all of Earth’s ecosystems as they had been working until then, the Atlantic Ocean off what is now the coast of Morocco was abuzz with large predators. We have added one more. An impressive specimen of mosasaurus over 8 meters long.
It is a mosasaur larger than any known modern shark or crocodile. Christened Pluridens serpentis, this newly discovered mosasaur could have had a hunting strategy reminiscent of modern sea snakes, but on a completely different scale when you consider its mammoth dimensions.
These marine lizards evolved and diversified during the Upper Cretaceous epoch, and their diversity peaked in the Maastrichtian Cretaceous era, between 72 and 66 million years ago.
While most of its relatives were small, only a few meters long , the new Moroccan species grew large , probably 8 meters long. It had long, slender jaws with numerous small, hooked teeth for grasping small prey such as fish and squid. Compared to related mosasaur species, this one had smaller eyes, suggesting that it had poor vision.
“Normally, when animals develop small eyes, it is because they depend more on other senses,” says Nick Longrich, paleontologist at the Milner Center for Evolution at the University of Bath and leader of the study published in the journal Cretaceous Research.
He hunted in shallow water where seeing was easy. Its snout was covered with small openings for nerves, which probably functioned similarly to those of sea snakes, which use them to detect changes in water pressure, indicating the presence of possible prey.
“If he wasn’t using his eyes, then most likely he was using his tongue to hunt, like a snake. Many aquatic snakes and lizards (such as sea snakes) move their forked tongues underwater, using chemical signals to track their prey, “continues the researcher.
Although paleontologists did not find a complete fossil of this species, the size of the skulls suggests that they grew around 6 meters and according to another of the remains, one of them would have been much larger, perhaps more than 10 meters long. Quite a Titan.
An area of incredible diversity
P. serpentis is the thirteenth species of mosasaur discovered in Morocco, including two other species of Pluridens. Not all would have existed simultaneously, but it is still a considerable number, especially considering that the same seas were also home to plesiosaurs, large sharks and crocodiles. It is undoubtedly a region of astonishing diversity of large predators.
“The diversity of these fossils is amazing. Far from diminishing in diversity, mosasaurs appear to be peaking just before going extinct, ”Longrich says.
Referencia: Nicholas R. Longrich et al. Pluridens serpentis, a new mosasaurid (Mosasauridae: Halisaurinae) from the Maastrichtian of Morocco and implications for mosasaur diversity. Cretaceous Research, published online May 8, 2021; doi: 10.1016/j.cretres.2021.104882
