An almost-complete fossil of the plant-eating Heterodontosaurus tucki dinosaur, which was found in South Africa, is currently being studied under the largest X-ray machine in the world, the European Synchrotron in Grenoble, France.
The Heterodontosaurus in question was about the size of a small cat, and lived about 200 million years ago, although it’s believed the species could grow as long as 1.7m. This fossil was found in a riverbed on a private farm near Grahamstown in 2005.
Project co-leader and Wits Professor Jonah Choiniere explained that the scanning of the specimen will be able shed some new light on the habits of Heterodontosaurus and other plant-eating dinosaurs.
Heterodontosaurus was rather unique, in the sense that it had different sets of teeth in its jaw. Normally herbivores have one set of teeth (molars), but this one has grinding teeth in the back of the jaw and big canines in the front.
“There’s still a lot we don’t know about early plant-eating dinosaurs and we need new specimens like this one and new technology like the synchrotron to fill in those gaps,” he said.
It is being X-rayed because the fossil is embedded in hard rock, which the fossil is too delicate to extract from. So, an X-ray is the next best thing to see what is going on in the inside.
As an example of some of the things the scientists will be looking for, the initial scans it revealed that the fossil was more than likely a juvenile.
“The skull bones aren’t strongly sutured together. On the first scans we can see the openings in the skull which are for the balance organs. We can digitally reconstruct the balance organs of the animal and tell how it held its head and how it interacted with its environment. That’s the sort of data you just can’t get by looking at a skull in 2D. So it’s very exciting,” says Choiniere.
The South African team also made a discovery which would have only been possible with the Synchrotron – and was initially missed with equipment at Wits.
“On the skull scan we can see bright white spots which are metallic inclusions. The reason we came to the synchrotron in the first place is that a CT scanner can’t generate sufficient X-rays to penetrate those metals. They appear as bright white spots here but you can see bone all around. When we did this in our lab at the University of Witwatersrand all you could see was the metals so it looked like there was no bone in the specimen. So right here you can see the advantage of having a synchrotron beam to focus on the specimen,” he said.
South Africa has access to the Grenoble facility by virtue of being a member country of the European Synchrotron Radiation Facility (ESRF). Palaeoscientists based at the ESRF and in South Africa helped with the project.
Thanks to that collaboration, more specimens could be scanned in the future.
“The rocks of the Karoo from South Africa have yielded an extraordinary amount of amazing fossils. Since South Africa has joined as a member country, we were able to scan a lot of these fossils and work on projects that were not accessible before,” explained ESRF’s Dr Vincent Fernandez.
Here is something else that most people won’t know: the world’s oldest dinosaur embryos also originated from South Africa.[Images – Supplied/B. de Klerk]