Researchers have unearthed fossils belonging to two previously unidentified species of dinosaurs in Morocco, challenging the notion that dinosaurs were on the decline prior to the cataclysmic asteroid event that occurred 66 million years ago. These new findings indicate that a diverse range of carnivorous dinosaurs continued to flourish in North Africa up until their sudden demise. Credit: Andrey Atuchin
In Morocco, paleontologists have discovered fossils of early relatives of the Tyrannosaurus rex, distinguished by their compact snouts and diminutive forelimbs. These newfound species belong to the Abelisauridae family, the southern hemisphere’s carnivorous analogs to the northern hemisphere’s tyrannosaurs. Discovered in strata dating to the terminal stages of the Cretaceous period, these specimens highlight the abundant diversity of dinosaur species in Africa shortly before their mass extinction 66 million years ago due to an asteroid impact.
Two distinct species of dinosaurs were excavated from late Cretaceous deposits near Casablanca, Morocco. One species, located close to the town of Sidi Daoui, is evidenced by a pedal bone from a carnivore approximately two and a half meters (eight feet) in length. The second, unearthed near Sidi Chennane, is represented by the tibia of a carnivorous dinosaur that grew to an estimated five meters (15 feet) long.
Both species were members of the Abelisauridae family, a group of archaic meat-eating dinosaurs. They coexisted with the larger abelisaur Chenanisaurus barbaricus, supporting the idea that Morocco was a habitat for a multitude of dinosaur species just prior to the catastrophic asteroid impact that marked the conclusion of the Cretaceous period and the age of dinosaurs.
Fossil abelisaur tibia. Credit: University of Bath
Dr. Nick Longrich, affiliated with the Milner Centre for Evolution at the University of Bath, spearheaded the research. He remarked, “What is surprising is that these fossils were found in marine sediments. This was a shallow, tropical sea teeming with plesiosaurs, mosasaurs, and sharks. It is not a habitat where one would typically expect to discover a plethora of dinosaurs, but we are.”
Despite dinosaurs constituting a minor fraction of the fossil record in the region, the abundance of fossils offers the most comprehensive snapshot of African dinosaurs at the close of their era. The deposits have yielded a variety of species, providing evidence for a notably diverse dinosaur ecosystem.
Up to this point, the limited fossils unearthed represent five distinct species: a small hadrosaur known as Ajnabia, a long-necked titanosaur, the sizable abelisaur Chenanisaurus, and the two newly discovered abelisaurs.
Fossil abelisaur metatarsal. Credit: Nick Longrich, University of Bath
Dr. Longrich added, “We have other fossils currently under analysis, so it would be premature to discuss them in detail. However, the diversity of dinosaur species we are uncovering is indeed astonishing.”
Approximately 66 million years ago, the last dinosaurs disappeared along with up to 90% of Earth’s species, including mosasaurs, plesiosaurs, pterosaurs, and ammonites. The exact mechanisms of this end-Cretaceous extinction have been a subject of scholarly debate for over two centuries. A colossal asteroid impact in the Yucatan Peninsula is commonly implicated, but some theories suggest that dinosaurs might have been in decline beforehand. These Moroccan discoveries posit that dinosaurs remained diverse and ecologically successful in North Africa until their ultimate extinction.
Dr. Longrich observed, “While the end-Cretaceous period in western North America showed declining diversity, it’s not representative of global conditions. Climate changes, specifically cooling trends, may have influenced dinosaur diversity in higher latitudes, but information about dinosaurs from lower latitudes is scarce.”
At least in Morocco, the findings suggest that dinosaurs maintained a robust and varied ecosystem up to the point of their extinction.
Nour-Eddine Jalil, a professor at the Natural History Museum and researcher at Universite Cadi Ayyad in Morocco, who co-authored the paper, noted, “While T. rex was the apex predator in North America, abelisaurs occupied the same ecological niche in North Africa. Despite the infrequency of dinosaur fossils, they corroborate the abundance of marine reptile remains in indicating that biodiversity was flourishing rather than diminishing prior to the Cretaceous-Paleogene transition.”
Reference: “New Fossils of Abelisauridae (Dinosauria: Theropoda) from the Upper Maastrichtian of Morocco, North Africa” by Nicholas R. Longrich, Erik Isasmendi, Xabier Pereda-Suberbiola and Nour-Eddine Jalil, 22 August 2023, Cretaceous Research.
DOI: 10.1016/j.cretres.2023.105677
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Frequently Asked Questions (FAQs) about Abelisaurid Dinosaurs in Morocco
What new dinosaur species have been discovered in Morocco?
Two previously unidentified species of Abelisaurid dinosaurs have been discovered in Morocco. These species are early relatives of the Tyrannosaurus rex and are notable for their compact snouts and diminutive forelimbs.
Where were these new dinosaur species found?
The fossils were unearthed in late Cretaceous deposits near Casablanca, Morocco. One species was located close to the town of Sidi Daoui, and the other was found near Sidi Chennane.
What is significant about these new findings?
These discoveries challenge the prevailing notion that dinosaurs were already in decline before the asteroid impact that led to their extinction 66 million years ago. The newly identified species indicate that a diverse range of carnivorous dinosaurs were flourishing in North Africa up until their sudden demise.
Who led the research team that made these discoveries?
The research was led by Dr. Nick Longrich, who is affiliated with the Milner Centre for Evolution at the University of Bath.
Were these dinosaurs similar to the Tyrannosaurus rex?
Yes, the newly discovered species are considered early relatives of the Tyrannosaurus rex. However, they are members of the Abelisauridae family, which served as the southern hemisphere’s carnivorous counterparts to the northern hemisphere’s tyrannosaurs.
What do these discoveries suggest about the ecosystem of the time?
The discoveries indicate that North Africa was home to a robust and varied ecosystem of dinosaurs. The region was so rich in fossils that it offers the most comprehensive snapshot of African dinosaurs at the close of their era.
What are abelisaurs?
Abelisaurs are a family of primitive carnivorous dinosaurs known for their short arms and stout snouts. They lived alongside larger abelisaurs like Chenanisaurus barbaricus and are considered the southern hemisphere’s answer to the northern hemisphere’s tyrannosaurs.
How do these discoveries contribute to our understanding of the mass extinction event?
These findings provide evidence that contradicts theories suggesting dinosaurs were in decline before the mass extinction event. They show that a diverse and flourishing population of dinosaurs existed in North Africa right up to the point of their extinction due to the asteroid impact.
What other types of fossils were found in the same region?
In addition to the dinosaur fossils, the region is abundant in marine fossils, including plesiosaurs, mosasaurs, and sharks. Despite being a marine environment, it surprisingly yielded a variety of dinosaur species.
How many different species of dinosaurs have been identified in this region so far?
So far, five distinct species of dinosaurs have been identified: a small hadrosaur known as Ajnabia, a long-necked titanosaur, the large abelisaur Chenanisaurus, and the two newly discovered abelisaurs.
More about Abelisaurid Dinosaurs in Morocco
- Milner Centre for Evolution at the University of Bath
- Cretaceous Research Journal
- About Abelisauridae Family
- Extinction Event 66 Million Years Ago
- Paleontology in Morocco
- Nour-Eddine Jalil’s Research
- The Cretaceous Period
- Asteroid Impact Theory
- Diversity in Late Cretaceous Dinosaurs
