World's oldest dinosaur found in museum storeroom
A set of fossilised bones kept for more than half a century in the
dusty storerooms of the Natural History Museum in London belonged to the
earliest-known dinosaur to roam the land.
Scientists have confirmed that the fossils, which were first
unearthed in the 1930s in Tanzania, are those of a Labrador-sized
dinosaur that lived at least 10 to 15 million years earlier than the
previous oldest-known dinosaur.
The dinosaur probably stood upright on two legs and was between two
and three metres long with a metre-long tail. However, scientists do not
know whether it was a carnivore or herbivore because no teeth or jaws
were preserved. They have named the extinct species Nyasasaurus
parringtoni after Africa's Lake Nyasa, now called Lake Malawi, and
Cambridge University's Rex Parrington, a palaeontologist who discovered
the fossils in East Africa.
Parrington handed over the rocks and fossilised bones to his PhD
student, Alan Charig, who carried out an initial assessment of the bones
in the 1950s and was still working on the project at the Natural History
Museum when he died in 1997.
The fossils were then stored away again until they were re-examined
by a team from Britain and the US. They found the creature's arm bones
bear the key characteristics of dinosaurs and that it must have grown
rapidly, another distinguishing feature of dinosaurs. The fossils have
been dated to between 247 million and 235 million years ago, a
geological period known as the Triassic when Africa was part of a giant
supercontinent called Pangaea, which included South America, the
Antarctic and Australia. “If the newly named Nyasasaurus parringtoni is
not the earliest dinosaur, then it is the closest living relative found
so far,” said Sterling Nesbitt of the University of Washington in
Seattle, who collaborated on the study published in the journal Biology
Letters.
“It establishes that dinosaurs likely evolved earlier than previously
expected and refutes the idea that dinosaur diversity burst onto the
scene in the Late Triassic [Period], a burst of diversification unseen
in any other groups at that time,” Dr Nesbitt said.
Paul Barrett, a dinosaur expert at the Natural History Museum, said:
“Although we only know Nyasasaurus from fossil fragments, the anatomy of
its upper arm bone and hips have features that are unique to dinosaurs,
making us confident that we're dealing with an animal very close to
dinosaur origin.”
Dinosaur fossils are found throughout the world. However, the
discovery confirms that dinosaurs probably originated in the southern
hemisphere and migrated north, probably with the movement of the
continents.
“These new findings place the early evolution of dinosaurs and
dinosaur-like reptiles firmly in the southern continents,” Dr Barrett
said.
- The Independent
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