In Morocco, scientists have discovered the fossils of archaic T. rex relatives with short bulldog-like snouts and even shorter limbs. The two new dinosaur species are members of the Abelisauridae, a family of carnivorous dinosaurs that were the Southern Hemisphere’s counterparts to tyrannosaurs. They lived at the close of the Cretaceous period and demonstrate that dinosaur diversity existed in Africa prior to their extinction 66 million years ago.
Two new dinosaur species from the end of the Cretaceous have been discovered in Morocco, just outside of Casablanca. A two-and-a-half-meter-long (eight-foot-long) foot bone of a predator was discovered near the town of Sidi Daoui, representing one species. The other specimen, from nearby Sidi Chennane, is the thigh bone of a five-meter-long (15-foot-long) carnivore.
Both belonged to the family of primitive carnivorous dinosaurs known as abelisaurs and coexisted with the much larger abelisaur Chenanisaurus barbaricus, demonstrating that Morocco was home to numerous dinosaur species just before a massive asteroid wiped out the dinosaurs at the end of the Cretaceous Period.
The research, conducted by Dr. Nick Longrich of the Milner Center for Evolution at the University of Bath, was published in Cretaceous Research. “What’s surprising here is that these are marine beds. It’s a shallow, tropical sea full of plesiosaurs, mosasaurs, and sharks. It’s not exactly a place you’d expect to find a lot of dinosaurs. But we’re finding them.”
Even though dinosaurs make up a minor portion of fossils, the region is so rich in fossils that it has provided the clearest picture of African dinosaurs from the end of the dinosaur period.
Instead of discovering the same few species, paleontologists frequently recover fossils of new species, indicating that the dinosaur fauna inhabiting these deposits is exceptionally diverse.
Unveiling New Dinosaur Discoveries: From Tiny Duckbills to Giant Titans
A small duckbill dinosaur named Ajnabia, a long-necked titanosaur, the gigantic abelisaur Chenanisaurus, and now the two new abelisaurs have been identified from the limited number of dinosaur fossils that have been discovered to date.
Dr. Longrich stated, “We have other fossils as well, but they’re currently under study. So we can’t say much about them at the moment, except that this was an amazingly diverse dinosaur fauna.”
Approximately 66 million years ago, the last dinosaurs died out, along with as much as 90 percent of all species on Earth, including mosasaurs, plesiosaurs, pterosaurs, and ammonites. The pattern and causes of the end-Cretaceous extinction have been the subject of debate for over 200 years.
The extinction of dinosaurs has been attributed to a massive asteroid impact on the Yucatan peninsula, although it has been argued that dinosaurs were already in decline. Dinosaurs thrived in North Africa until the very end, as evidenced by the Moroccan dinosaurs.
Longrich stated that “The end of the Cretaceous in western North America definitely seems to become less diverse at the end.” “But that’s just one small part of the world. It’s not clear that you can generalize from the dinosaurs of Wyoming and Montana to the whole world.
“It also grew colder near the end, so it might not be surprising if dinosaurs at higher latitudes became less diverse. But we don’t know much about dinosaurs from lower latitudes.”
At least in Morocco, they appear to have remained diverse and prosperous until the end.
“When T. rex reigned as a megapredator in North America, abelisaurus sat at the top of the food chains in North Africa,” said Nour-Eddine Jalil, professor at the Natural History Museum and researcher at Universite Cadi Ayyad in Morocco and co-author of the paper.
“The dinosaur remains, despite their rarity, give the same messages as the more abundant marine reptile remains. They tell us that, just before the Cretaceous-Paleogene crisis, biodiversity was not declining but on the contrary, was diverse.”