First fossil of a duck-billed dinosaur discovered in Africa

Duck-billed dinosaurs evolved in North America and spread to South America, Asia, Europe and eventually Africa. Photo credit: Raul Martin

The first fossils of a duck-billed dinosaur were discovered in Africa, suggesting that the dinosaurs crossed hundreds of kilometers of open water to get there.

The study, published in plaster Research, bring back the new dinosaur, Ajnabia odysseus, from the rocks in Morocco at the end of the Cretaceous period 66 million years ago. Ajnabia was a member of the duck-billed dinosaurs, various herbivorous dinosaurs that grew up to 15 meters in length. But the new dinosaur was tiny compared to its relatives: only three meters long, it was the size of a pony.

Duckbills developed in North America and eventually spread to South America, Asia, and Europe. Since Africa was an island continent in the late Cretaceous, isolated by deep-sea routes, it seemed impossible to get there for the duck’s beaks.

The discovery of the new fossil in a mine just hours from Casablanca was “the last thing you would expect in the world,” said Dr Nicholas Longrich of the Milner Center for Evolution at the University of Bath, who led the study. . Dr Longrich said: “It was completely out of place, like finding a kangaroo in Scotland. Africa was completely isolated from water: how did you get there? ”

The silhouette shows Ajnabia’s size relative to humans and the contemporary dinosaur fauna of Maastricht in Morocco. Photo credit: Dr. Nick Longrich

Study of AjnabiaThe characteristic teeth and jawbones indicate that it belonged to Lambeosaurinae, a subfamily of duckbills with ornate bony crests. Lambeosaurs evolved in North America before spreading to Asia and Europe, but have never been found in Africa.

They traced the development of duckbills and found that lambeosaurs evolved in North America and then spread to Asia across a land bridge. From there they colonized Europe and finally Africa.

Since Africa was secluded by deep oceans at the time, duckbills must have rafted hundreds of miles over rubble, swam, or swam to colonize the continent. Duckbills were likely powerful swimmers – they had large tails and strong legs and are often found in river debris and ocean rocks, so they may have simply swam for the distance.

“Sherlock Holmes said that once you have eliminated the impossible, everything that is unlikely must be the truth,” Longrich said. “It was impossible to go to Africa. These dinosaurs evolved long after continental drift separated from continents and we have no evidence of land bridges. Geology tells us that Africa has been isolated from the oceans. If so, the only way to get there is water. ”

In relation to this feat the dinosaur is called “Ajnabia odysseus.Ajnabi in Arabic means “foreigner” and Odysseus refers to the Greek navigator.

Map showing the location of duck-billed dinosaurs during the Late Cretaceous period. Photo credit: Dr. Nick Longrich

Ocean crossings are rare and unlikely events, but they have been observed in historical times. In one case, green iguanas traveled over rubble between Caribbean islands during a hurricane. In another case, a Seychelles tortoise flew hundreds of kilometers across the Indian Ocean to wash up in Africa.

“Over the course of millions of years,” Longrich said, “events are likely to happen many times in a century.” Ocean crossings are needed to explain how lemurs and hippos got to Madagascar or how monkeys and rodents got from Africa to South America. ”

The fact that duckbills and other groups of dinosaurs spread across continents even when sea levels are high suggests that dinosaurs also traveled across the oceans. “As far as I know, we are the first to suggest crossing the ocean,” Longrich said.

The international team of scientists was drawn from the University of Bath with researchers from the University of the Basque Country UVP / EHU (Spain), George Washington University (USA) and the Natural History Museum of Sorbonne University (France) / Universite Cadi Ayyad (Morocco).

Dr Nour-Eddine Jalil of the Natural History Museum of the Sorbonne University (France) said: “The sequence of unlikely events (crossing of an ocean by a dinosaur, fossilization of a terrestrial animal in a marine environment) underlines the rarity of our discovery and therefore its importance.

“”Ajnabia it shows us that hadrosaurs have entered African land and that ocean barriers are not always an insurmountable obstacle. ”

Reference: “The first duck-billed dinosaur (Hadrosauridae: Lambeosaurinae) from Africa and the role of ocean expansion in dinosaur biogeography” by Nicholas R. Longrich, Xabier Pereda Suberbiola, R. Alexander Pyron and Nour-Eddine Jalil , November 2, 2020, Research on plaster.
DOI: 10.1016 / j.cretres.2020.104678