Science news
By James Ashworth
First published 18 March 2025
The earliest example of an important and widespread group of dinosaurs has been found in North Africa.
A leg bone fragment found in Morocco is the first sign of the cerapodans, which became Earth’s dominant herbivores for tens of millions of years.
An ancient relative of Iguanodon, Triceratops and Pachycephalosaurus once roamed northern Africa.
Collectively known as the cerapodans, this large dinosaur group included important herbivores during the Cretaceous Period between 145 and 66 million years. But while preserved footprints show these animals had already evolved by the Middle Jurassic some 20 to 30 million years earlier, very few of their fossils have been found.
A newly described leg bone from Morocco has provided new evidence for scientists navigating the evolution of these dinosaurs. While the femur may be small and fragmented, it’s still the oldest evidence of the cerapodans found anywhere on Earth.
Dr Susannah Maidment, who led the research into the fossil, says that it highlights the importance of Morocco for understanding the evolution of many dinosaurs.
“We’ve already found the world’s oldest ankylosaur and one of the oldest stegosaurs from this area of the Middle Atlas mountains,” Susannah explains. “It looks like the dinosaurs here are among the earliest members that we know of from some key clades, so it’s important to publish other fossils from this site to emphasise the significance of these rocks.”
The findings of the study were published in the journal Royal Society Open Science.
The murky Middle Jurassic
The Middle Jurassic is notoriously difficult to study because of its relative lack of land-based fossils. Volcanic eruptions in what is now southern Africa and Antarctica led to rapid and extreme climate change that caused sea levels to rise sharply.
As a result, there was less space for the fossils of land-based animals during this time. This means that fossils of dinosaurs, pterosaurs and other Middle Jurassic wildlife are very rare.
But what has been found suggests that it was an important time of transition for life on Earth. Pterosaurs were evolving into more diverse forms, while dinosaurs were coming to dominate the planet’s ecosystems.
The cerapodans were no exception. When they first evolved, these were small dinosaurs like Hypsilophodon that walked on two legs and used their front limbs for grasping objects. But over time they got bigger, and footprints of what seem to be cerapodans have been found in countries including Morocco.
“We’ve seen bipedal, rounded footprints with three toes at a number of Middle Jurassic sites from around the world,” Susannah explains. “If you saw them in the Cretaceous you’d almost certainly say they were made by members of the Iguanodon family.”
Cerapodan body fossils, however, have been harder to come by. For some time, the oldest example was a 164-million-year-old thigh bone from Callovosaurus leedsi, a relative of Iguanodon discovered near Peterborough, United Kingdom.
Callovosaurus’s record, however, may have just been broken. A partial dinosaur skeleton from Skye, which Susannah recently helped to describe, could be a cerapodan that’s around two million years older. Unfortunately, its state of preservation makes it hard to know for certain.
The fossil from Morocco is around the same age as this Scottish dinosaur but can be more confidently identified as a cerapodan. While there’s not enough left of the animal to name it as a species, the researchers hope that they’ll be able to find more of the dinosaur in future research at the site.
Preserving Morocco’s fossil heritage
Though the cerapodan fossil’s scientific value might be limited, it’s a priceless part of Morocco’s ancient heritage. In fact, it’s become the first specimen added to the newly established fossil collection of the University Sidi Mohamed Ben Abdellah (USMBA) in Fes.
“The specimens we’ve previously described from this area have been purchased from commercial collectors and private fossil dealers, so it’s really nice that this is the first of many which will now be staying in Morocco,” adds Susannah. “We’re now up to 88 in the USMBA’s catalogue, and we hope there’ll be more on the way.”
By helping to develop palaeontology in the region, the team hope that more home-grown research will be able to take part in North Africa. As part of a collaboration between the USMBA, the Natural History Museum and the University of Birmingham, Susannah has also recently helped to set up a fossil preparation lab in Morocco.
“While we had originally planned to bring some fossils on a short-term basis to the UK to prepare them and then return them, this proved to be impossible,” she explains. “Instead, we sent the two students from the USMBA to be trained in fossil preparation in Egypt.”
“We’ve now brought them the equipment so they can prepare the fossils themselves. We prepared around 80 or so in a week on our recent trip and are planning to describe what we found in future research.”