When it comes to looks, the long-necked dinosaur Mansourasaurus shaninae isn’t all that remarkable. But the new species of sauropod is still turning heads among paleontologists.
Discovered in Egypt, the creature is one of the few dinosaur fossils found so far in Africa that dates to the late Cretaceous period, roughly 80 to 66 million years ago. This time marks the final chapter in the age of dinosaurs, which came to an abrupt end when a giant meteor smacked into what is now the Yucatán Peninsula.
Africa’s fossil record during the late Cretaceous is sparse, says study contributor and Carnegie Museum of Natural History paleontologist Matthew Lamanna. That means scientists aren’t sure which dinosaurs lived where across the continent during the period, and how much they mixed with dinosaurs on other ancient land masses.
Paleontologists at Mansoura University in Egypt discovered the Mansourasaurus fossils in the Sahara in 2013. Lamanna and a group of paleontologists from various research institutions then examined the fossil during work that was funded in part by the National Geographic Society. Their work categorizing the new species appears today in the journal Nature Ecology and Evolution.
“The end of the age of dinosaurs in Africa is one of the final frontiers for dinosaur paleontology,” Lamanna says. The new find “adds a bit of hard evidence to what African fauna was like” during this crucial time period.
When dinosaurs first emerged, they populated a single land mass made up of connected continents. But as those continents began to shift and break apart, many terrestrial dinosaurs became separated by vast oceans.
Some paleontologists theorized that, like modern-day Australia, Cretaceous Africa was essentially an island continent filled with unique species. Other experts suggested the African land mass still had ties to its neighbors.
“Was Africa an isolated continent, or were there connections with the land masses surrounding it?” asks Field Museum paleontologist Eric Gorscak. The new find, he says, suggests the latter. So far, Mansourasaurus seems very similar to Cretaceous sauropods found in Europe and Asia, suggesting that the Egyptian dinosaur did not evolve in isolation.
“It seems to suggest Africa was a mixture of Northern and Southern Hemisphere [dinosaurs],” he says.
The discovery therefore also provides clues about Cretaceous geography, says Michael Habib, a paleontologist from the University of Southern California who was not involved with the study.
By the end of the Cretaceous, the continents as we know them would have been in "modern-ish" positions, as he describes them. Sea levels, however, would have been higher, making it difficult for animals to swim across.
Whether Mansourasaurus might have walked over a land bridge, swam from closely positioned islands, or traveled in a yet-to-be-discovered way from Europe or Asia is unclear.
Part of why fossils have been so difficult to find in Africa is a matter of luck, adds Habib.
"You need the right kind of rocks exposed in the right way," to find intact fossils, he says. Underdeveloped infrastructure and political conflict have also made it difficult for paleontologists to find African dinosaurs.
Scientists at Mansoura University and Lamanna will continue searching for dinosaurs in Egypt.
"Our understanding of land animals will improve dramatically over the next few years," he predicts, "but we have a long way to go."