Last updated January 30, 2018 at 10:11 am
Fossil tells a previously unknown story about the evolution of Earth itself.
For hundreds of years we’ve been studying dinosaur fossils, but Africa around 100-66 million years ago is still a bit of a blank page. A new dinosaur discovery has started filling in those details, and also revealed far more about the Earth at that time than we expected.
In the Sahara Desert, palaeontologists from Mansoura University in Egypt have discovered the fossils of Mansourasaurus shahinae.
The dinosaur was huge – the length of a bus with a long-neck and bony plates embedded in its skin. And although it was found in today’s desert, it was a plant eater that lived on a coastline around 80 million years ago.
The sauropods of the Cretaceous
Mansourasaurus belongs to the Titanosauria, a group of sauropods (long-necked plant-eating dinosaurs) that were common throughout much of the world during the Cretaceous period (100-66 million years ago).
Titanosaurs are famous for including the largest land animals known to science, such as Argentinosaurus, Dreadnoughtus, and Patagotitan.
Mansourasaurus, however, is not a challenger to the largest Titanosaurs. In fact is was fairly moderate-sized – roughly the weight of an African elephant.
However what makes it special is not its size, but that it is the most complete dinosaur specimen so far discovered from the end of the Cretaceous period in Africa.
The researchers found parts of the skull, the lower jaw, neck and back vertebrae, ribs, most of the shoulder and forelimb, part of the hind foot, and pieces of dermal plates.
For palaeontologists, this was like the holy grail. They had been searching for a long time for a fossil like this from the end of the age of dinosaurs in Africa.
“Mansourasaurus shahinae is a key new dinosaur species, and a critical discovery for Egyptian and African paleontology,” said Dr Eric Gorscak, an author on the study.
“Africa remains a giant question mark in terms of land-dwelling animals at the end of the Age of Dinosaurs. Mansourasaurus helps us address longstanding questions about Africa’s fossil record and paleobiology – what animals were living there, and to what other species were these animals most closely related?”
Late Cretaceous dinosaur fossils in Africa are hard to come by – much of the land where their fossils might be found is covered in lush vegetation, rather than the exposed rock of dinosaur treasure troves such as those in the Rocky Mountain region, the Gobi Desert, or Patagonia.
This lack of a Late Cretaceous fossil record in Africa was frustrating for scientists since, around that time, the continents were undergoing massive changes, which was reflected in the evolution of animal species.
But that is where the new dinosaur’s value really shines through.
The evolution of continents
During the earlier eras of the dinosaurs, including the Triassic and Jurassic periods, all the continents were joined together as one giant landmass – the supercontinent of Pangaea. However, during the Cretaceous Period, Pangaea began splitting apart and shifting towards the continents as we see today.
The question always remained however as to how well-connected Africa was to other Southern Hemisphere landmasses and Europe during this time, and in particular, to what degree Africa’s animals may have been cut off from their neighbours and evolved on their own separate path.
Mansourasaurus, as one of the few African dinosaurs found from this period, has finally shed some light on that question.
By analysing features of its bones, the team determined that Mansourasaurus is more closely related to dinosaurs from Europe and Asia than it is to those found farther south in Africa or in South America.
This shows that at least some dinosaurs could move between Africa and Europe near the end of these animals’ reign. “Africa’s last dinosaurs weren’t completely isolated, contrary to what some have proposed in the past,” says Gorscak. “There were still connections to Europe.”
The start of a new era of dinosaurs in Africa
In a single discovery, not only has Mansourasaurus shahinae started filling in the missing chapter of African dinosaur history, but it revealed more about the way that dinosaurs moved and evolved, and answers questions about the evolution and development of the very continents themselves as well.
However, the revelations may yet continue. The leader of the university’s Vertebrate Palaeontology research, Dr Hesham Sallam, expects that Africa will start to give up more dinosaur secrets. “What’s exciting is that our team is just getting started. Now that we have a group of well-trained vertebrate palaeontologists here in Egypt, with easy access to important fossil sites, we expect the pace of discovery to accelerate in the years to come.”
The paper has been published in Nature Ecology and Evolution