New dinosaur gives glimpse into the past
A new dinosaur has been discovered by a young scientist now at the University
of the Witwatersrand. It is the oldest known member of the family that included
the great giants of the dinosaur world, and provides valuable new information on
the early development of the colossal creatures of prehistory.
The dinosaur has been named Antetonitrus ingenipes. The genus name (Antetonitrus)
means 'Before the Thunder', and the species name (ingenipes) means
'Massive Feet'.
It was announced in early July 2003 by Dr Adam Yates (31), a postdoctoral
researcher at the Bernard Price Institute for Palaeontological Research (BPI) in
Johannesburg, South Africa.
Biggest land animal of its time
Antetonitrus lived 210-215 million years ago, and was the biggest land animal
of its time. It was about 10 metres long from its nose (at the end of its long
neck) to the tip of its long tail, and would have weighed in the region of 1.8
tonnes.
Yates recognised that fossil bones first unearthed in the early 1980s, part
of the BPI collection, were actually those of a very early sauropod dinosaur.
Investigation and research over two years finally convinced him the fossils were
those of a new dinosaur, and that they represented the most complete early
sauropod ever found.
Said Yates: "I came to South Africa for the first time in 2001 as part
of a research project for the University of Bristol. That was when I saw the
fossil bones that had been found in the Ladybrand District of the Free State by
the legendary palaeontologist Professor James Kitching. They had been classified
as prosauropod ('Before the Lizard Feet'), but I knew straight away they were
not."
Yates took notes, sketches and photographs of the fossils back to England for
intensive study. The following year (2002) he returned to South Africa to join a
research expedition, and took the opportunity to examine the fossils further and
take a series of digital images. He was also able to travel to Bloemfontein to
compare the fossils with those of an early dinosaur in the National Museum.
210 -215 million years old
By the end of that year, Yates was convinced the skeletal remains were those
of a sauropod dinosaur that had lived in the late Triassic Period, 210-215
million years ago. "This was very exciting, because the only early sauropod
known was from the very end of the Triassic, right on the boundary of the
Jurassic period. This meant the South African dinosaur was millions of years
older, from the very beginning of the dinosaur age.
"In other words, these fossils could teach us things about the earliest
dinosaurs that we had never known before."
Antetonitrus shows a mixture of primitive and advanced characteristics. Its
four legs were practically of equal length and its foot was very short, showing
that it walked slowly and four-footed (as opposed to the early prosauropod
dinosaurs whose front legs were shorter than their back legs, and who could
stand and walk two-legged).
Said Yates: "This is the earliest evidence we have of dinosaurs walking
permanently on four short, solid feet. It shows that the characteristic body
form of the long-necked dinosaurs, which allowed the later animals to grow to
such gigantic sizes, evolved quite rapidly and much faster than we had
previously thought."
He said that the bones of the inner toes of the hind feet were thicker than
the middle toe bones, indicating that weight distribution was biased to the
inner part of the foot. In other words, the dinosaur was a bit pigeon-toed. In
addition, the innermost toe - equivalent to the human big toe - had an
exceptionally large claw that was probably used in defensive kicking.
Antetonitrus shared one characteristic with its prosauropod cousins: its front
foot, which was not locked into a forward-facing position like later sauropods,
had a mobile clawed thumb that could grasp as well as swipe at any predators.
"Although we don't have the skull of the animal we do have some neck
bones, and together with the other bones we can get a very good idea of the
size, shape and certain habits of Antetonitrus," said Yates. "We can
conclude, for example, that it was a pure herbivore as opposed to an
opportunistic eater that mixed its plant diet with meat - again, a
characteristic that we previously thought had developed much later."
What happened to Antetonitrus?
Yates's Antetonitrus was not fully grown. "It was an adolescent,"
he said, "because its backbones had not yet fused. It was about 10 metres
long when it was alive, which means it was not a small animal. In fact it was
the largest land animal of its time, towering over everything else - including
the predators."
It was found with some fossilised bones of a younger juvenile, but Yates is
loath to speculate on whether or not the two dinosaurs were members of the same
family group. "We don't have enough information for that. We're not even
sure how they died, although the fact that one half of the older skeleton is
better represented than the other half suggests the animal was lying on the
ground after it died and was partially eaten by scavengers."
Dr Yates will be visiting the site of the discovery and is hoping to find out
more about how his dinosaur died. "Perhaps we might even be lucky enough to
find some more fossils in the area," he said. "It's obviously an
important site that could shed more light on the first of the giant dinosaurs.
"South Africa's fossil heritage is very rich indeed, and there's no
doubt that there are more dinosaurs waiting out there to be found."
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