The first fossils of platypus have been discovered in Africa, suggesting that the dinosaurs crossed hundreds of kilometers of open water to get there.
Research, published in Cretaceous period Research and report on new dinosaurs, Ajnabia odysseus, from the Moroccan rocks dating back to the late Cretaceous, 66 million years ago. Ajnabia was a member of the platypus, a diverse plant-eating dinosaur that was up to 15 meters long. But the new dinosaur was very small for its relatives – only 3 meters long, it was the size of a foal.
The platypus developed in North America and eventually spread to South America, Asia and Europe. Because Africa was an island continent in the Late Cretaceous period, isolated by deep sea lanes, the speculum seemed inaccessible.
Dr Nicholas Longrich, of the Milner Evolution Center at the University of Bath, who led the study, said: “The discovery of a new fossil in a mine a few hours from Casablanca is“ the last thing in the world. that you expect. . “It’s completely out of place, like finding a kangaroo in Scotland,” said Dr. Longrich. Africa was completely isolated by water – so how did they get there? “
Research about AjnabiaIts distinctive teeth and jaw bones indicate that it belonged to the Lambeosaurinae, a subfamily of the platypus with an intricately bony-shaped tip. Lambeosaurs evolved in North America before spreading to Asia and Europe, but have never been found in Africa before.
Studying on platypus evolution, they discovered that lambeosaurs evolved in North America, then spread over a land bridge to Asia. From there, they conquered Europe, and eventually Africa.
Because Africa was isolated by the deep oceans at the time, the platypus had to cross hundreds of kilometers of open water rafting on debris, floating or swimming – to capture the continent. Platypus are probably vigorous swimmers – they have large tails and strong legs, and are often found in river sediments and sea rocks, so they can only swim from afar.
“Sherlock Holmes said, once you eliminate the impossible, whatever remains, however unlikely, must be true,” said Longrich. “Can’t walk to Africa. These dinosaurs evolved long after continental drift split continents, and we have no evidence of land bridges. Geology tells us that Africa is isolated by oceans. If so, the only way to get there is by water ”.
Referring to this feat, the dinosaur was named “Ajnabia odysseus.“Ajnabi is Arabic for” foreigner “, and Odysseus refers to Greek seafarers.
Sea crossings are rare, unlikely, but observed events in history. In one instance, green iguanas moved between the Caribbean islands during a hurricane caused by debris. In another case, a tortoise from the Seychelles drifted hundreds of kilometers across the Indian Ocean into Africa.
“Over millions of years, events that happen in a century can happen many times,” says Longrich. It takes sea trips to explain how lemurs and hippos get to Madagascar, or how monkeys and rodents cross the sea from Africa to South America ”.
But the fact that platypus and other dinosaur groups spread between continents, even at high sea levels, suggests dinosaurs have also traveled across the oceans. “As far as I know, we were the first to propose dinosaur crossings,” said Longrich.
An international group of scientists led by the University of Bath together with researchers from Basque Country University UVP / EHU (Spain), George Washington University (USA) and University’s Museum of Natural History Sorbonne (France) / Universite Cadi Ayyad (Morocco).
Dr. Nour-Eddine Jalil, from the Sorbonne University’s (France) Natural History Museum, said: “The continuity of impossible events (dinosaurs crossing the ocean, fossils of terrestrial animals in the marine environment) highlights its rarity and hence its importance.
“Ajnabia shows us that tyrannosaurs have landed on the African mainland, tells us that ocean barriers are not always insurmountable ones.
Reference: “The first platypus (family Hadrosauridae: Lambeosaurinae) from Africa and the role of ocean floor scattering in dinosaur geology” by Nicholas R. Longrich, Xabier Pereda Suberbiola, R. Alexander Pyron and Nour-Eddine Jalil, November 2, 2020, Research in the Cretaceous period.
DOI: 10.1016 / j.cretres.2020.104678