Scientists
have unearthed in a Sahara Desert oasis in Egypt fossils of a long-necked,
four-legged, school bus-sized dinosaur that lived roughly 80 million years ago,
a discovery that sheds light on a mysterious time period in the history of
dinosaurs in Africa.
Researchers
said on Monday the plant-eating Cretaceous Period dinosaur, named
Mansourasaurus shahinae, was nearly 33 feet (10 metres) long and weighed 5.5
tons (5,000 kg) and was a member of a group called titanosaurs that included
Earth’s largest-ever land animals. Like
many titanosaurs, Mansourasaurus boasted bony plates called osteoderms embedded
in its skin.
Mansourasaurus,
which lived near the shore of the ancient ocean that preceded the Mediterranean
Sea, is one of the very few dinosaurs known from the last 15 million years of
the Mesozoic Era, or age of dinosaurs, on mainland Africa. Madagascar had a
separate geologic history.
Its
remains, found at the Dakhla Oasis in central Egypt, are the most complete of
any mainland African land vertebrate during an even larger time span, the
roughly 30 million years before the dinosaur mass extinction 66 million years
ago, said paleontologist Hesham Sallam of Egypt’s Mansoura University, who led
the study published in the journal Nature Ecology and Evolution. The
scientists recovered parts of its skull, lower jaw, neck and back vertebrae,
ribs, shoulder and forelimb, back foot and osteoderms.
A
lot of Africa is covered in grasslands, savannas and rain forests that obscure
underlying rock where fossils may be found, said postdoctoral researcher Eric
Gorscak of the Field Museum in Chicago, who was formerly at Ohio University.
While
as massive as a bull African elephant, Mansourasaurus was modestly sized next
to titanosaur cousins such as South America’s Argentinosaurus, Dreadnoughtus
and Patagotitan and Africa’s Paralititan, some exceeding 100 feet (30 metres)
long.
“Mansourasaurus,
though a big animal by today’s standards, was a pipsqueak compared to some
other titanosaurs,” said paleontologist Matt Lamanna of the Carnegie Museum of
Natural History in Pittsburgh.
The
researchers determined Mansourasaurus was more closely related to European and
Asian titanosaurs than to those from elsewhere in Africa and other Southern
Hemisphere land masses including South America formerly joined in a
super-continent called Gondwana.
“This,
in turn, demonstrates for the first time that at least some dinosaurs could
move between North Africa and southern Europe at the end of the Mesozoic, and
runs counter to long-standing hypotheses that have argued that Africa’s
dinosaur faunas were isolated from others during this time,” Lamanna said.
