Staff Writer
A UNIQUE species of dinosaur has been discovered in South Africa – but not in a hole dug by palaeontologists somewhere in the veld.
This one was discovered in a box in a museum.
The 200 million-year-old dinosaur had been found in the late 1930s in the Zastron area, about 30km south-east of the Lesotho border. For many decades it stayed in a box on a shelf at the Evolutionary Science Institute in Johannesburg.
One of the unique features of this dinosaur was an ankle bone bearing a cross. Because of this, and as it was found near the Lesotho border, the fossil has been named Sefapanosaurus, from “sefapano” in Sesotho, meaning “cross”.
Some years ago a palaeontologist studied the fossil and categorised it as yet another South African dinosaur, Aardonyx.
Recently, however, doctoral student Emil Krupandan from UCT’s department of biological sciences had a look at the remains and realised he was on to something quite new.
It turned out that not only was he looking at a “new” dinosaur entirely, but it fell into that special category of “transitional” dinosaurs – those that evolved from the smaller two-legged creatures to the massive four-legged dinosaurs.
“So it fills a gap, by showing the evolutionary pathway between the two,” Krupandan said.
Argentinian palaeontologist Alenjandro Otero, lead author on the publication on Sefapanosaurus, said: “Sefapanosaurus helps to fill the gap between the earliest sauropodomorphs and the gigantic sauropods.
It is a member of the growing list of of transitional sauropodomorph dinosaurs from Argentina and South Africa that are increasingly telling us about how they diversified.”
This dinosaur was 2m tall and about 6m long.
The bones that had been excavated included those of feet, other limbs and of vertebrae.
What was the eureka moment that led Krupandan to realise it was a unique fossil?
Well, he explains, the differences were small, and would not really be apparent to someone not very familiar with fossils of this kind.
“It was a very subtle kind of eureka moment: the angle of part of the heel bone; a slightly deeper depression here, or a little ridge there. I noticed stuff like that, mainly on the foot bones. Each dinosaur has a certain morphology, and the differences are subtle.”
Krupandan was not surprised that the skeleton lay there so long before it was found to be of a different kind, or that an earlier researcher had described it incorrectly.
“Wits University has a massive collection of fossils that have been excavated and are in boxes, and there is often lots of stuff waiting years to be processed. Those that are obviously different are pushed to the front of the queue and the rest wait.”
He says since the earlier researcher had examined the fossil, a larger body of knowledge on dinosaurs had been built which he could draw on, unlike his predecessor.