The first discovery of duckbill fossils in Africa offers an insight into how dinosaurs might have crossed the open ocean to arrive at the continent.
An international team of researchers published their findings in the journal Cretaceous Research, detailing the discovery of a new dinosaur called Ajnabia odysseus. The fossil of the new duckbill species was found embedded in rocks in Morocco, dating back to the end of the Cretaceous period some 66 million years ago.
The new species is a member of the same group as the duckbill dinosaurs, Hadrosauridae, which are mostly herbivorous and grew up to lengths of almost 50 feet (15 meters). This new species, however, was relatively small at only 10 feet (3 meters) long.
A Discovery Out of Place
Members of the hadrosaur family trace its origins in what is now North America, later migrating and covering parts of South America, Asia, and Europe. On the other hand, Africa was an isolated island continent during the Late Cretaceous, separated by deep waterways, creating the notion that duckbill dinosaurs could not have reached the African continent.
It explains why the recent discovery of a separate duckbill species in a mine located a few hours outside Casablanca, Morocco's largest city, was "about the last thing in the world you would expect," according to Dr. Nicholas Longrich - the study leader from the Milner Centre for Evolution at the University of Bath in England. In a press release from the University, Dr. Longrich likened the archaeological dig to "finding a kangaroo in Scotland." The question is how this duckbill species got into a place completely surrounded by deep waters.
A study of the duckbill's distinct dental profile and its mandible placed it as a member of the Lambeosaurinae, a subgroup under the duckbill dinosaurs characterized by a large, bony crest on the top of its head. These crested duckbills also evolved first in North America before moving to Asia and Europe. Members of the lambeosaurus have not been found before in Africa.
Reaching Africa
Reconstructing the phylogenetic tree of duckbills, researchers proposed that lambeosaurs could have evolved in North America before crossing a land bridge to the Asian landmass. They moved next to what is now Europe before crossing over to the African continent.
Owing to Africa's physical separation with the other continents with waters - hundreds of kilometers wide - duckbills could have reached the new continent by rafting on debris, floating, or even swimming across. Researchers raised the possibility of duckbills being powerful swimmers, a fact supported by the presence of large tails and powerful legs reconstructed from previously discovered specimens. Additionally, most duckbill fossils were found embedded in marine rocks, or around river deposits, making swimming a possibility.
"Sherlock Holmes said, once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth," Longrich noted. While it was impossible to simply walk to Africa at the time, he noted that the duckbills evolved long after the continental drift sent Africa away from the rest. This leaves the possibility of only reaching Africa by water.
The name of the new species, Ajnabia odysseus, is from the Arab word for "foreigner" (Ajnabi), and the famous seafarer in Greek literature, Odysseus, or Ulysses to the Romans.
