* Discovery puts dinosaur origins 10-15 mln years earlier
* Fossil sat in London's Natural History Museum for decades
* Has features unique to dinosaurs
LONDON, Dec 5 (Reuters) - Researchers have found what could
be the earliest known dinosaur to walk the Earth lurking in the
corridors of London's Natural History Museum.
A mysterious fossil specimen that has been in the museum's
collection for decades has now been identified as most likely
coming from a dinosaur that lived about 245 million years ago -
10 to 15 million years earlier than any previously discovered
The creature was about the size of a Labrador dog and has
been named Nyasasaurus parringtoni after southern Africa's Lake
Nyasa, today called Lake Malawi, and Cambridge University's Rex
Parrington, who collected the specimen at a site near the lake
in the 1930s.
"It was a case of looking at the material with a fresh pair
of eyes," Paul Barrett from the Natural History Museum, who
worked on the study, told Reuters. "This closes a gap in the
fossil record and pushes back the existence of dinosaurs."
The London fossil was studied by researchers in the 1950s
but no conclusion was reached and nothing was published, said
Barrett. "It was a mystery what it was ... It just became this
Two features of the London fossil, together with a similar
sample subsequently spotted at the Iziko South African Museum in
Cape Town, are strong evidence that the animal belongs with the
dinosaurs, the researchers said.
The bone tissues in the upper arm show marks of rapid
growth, common in dinosaurs, and they also have a feature known
as an elongated deltopectoral crest that anchored the upper arm
muscles, a feature unique to dinosaurs.
"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," said Barrett.
The researchers believe Nyasasaurus probably stood upright,
was a metre tall at the hip, 2-3 metres long from head to tail,
and weighed 20-60 kg.
When it was alive, the world's continents were joined in a
vast landmass called Pangaea, and the area of Tanzania where the
fossils were found would have been part of the southern Pangaea
that included Africa, South America, Antarctica and Australia.
Theorists have long argued there should have been dinosaurs
walking the Earth in the Middle Triassic period, which ended
about 237 million years ago, but until now the evidence has been
ambiguous, said Sterling Nesbitt at the University of Washington
in Seattle who led the study, published in the journal Biology
"If the newly named Nyasasaurus parringtoni is not the
earliest dinosaur, then it is the closest relative found so
far," said Nesbitt.
"What's really neat about this specimen is that it has a lot
of history. Found in the '30s, first described in the 1950s ...
Now 80 years later, we're putting it all together."
The researchers plan further field work in Tanzania to find
more fossils and build a better picture of the animal's anatomy.
(Editing by Pravin Char)