Anteosaurus had the fangs of a killer, but with a heavy tail and weighing the same as a hippo, it was thought this lumbering beast fed on the leftovers of other carnivores.
But now new technology has peeled back 265 million years and revealed that size can be deceiving.
Anteosaurus was a stealthy killer that outran and stalked its prey, a new study is suggesting. And scientists know this because of X-ray imaging and 3D reconstructions of the predator’s skull.
“We were able to show that the brain and the ear had some adaptations for an animal that was tracking its prey very efficiently,” says Dr Julien Benoit of the Evolutionary Studies Institute at the University of the Witwatersrand. “And people used to think that it was basically a hippopotamus that could not really move.”
It was so big, it was even suggested that Anteosaurus might have lived in water.
Anteosaurus was a premamalian reptile that roamed what is now the Karoo 265 to 260 million years ago. This was a period before the dinosaurs.
But this doesn’t mean that Anteosaurus was as quick as a cheetah or had the lightning reflexes of a leopard. However in a land of other lumbering giants, Anteosaurus was quick.
“It was definitely more agile,” says Benoit.
The scan of the inner ear showed that the organ of balance in Anteosaurus was larger than its closest relatives. This suggested that this early predator was most likely capable of moving faster than its prey.
A further discovery was that the part of the brain that co-ordinates eye and head movement was large. Such an adaptation would have helped the animal track its prey.
“In creating the most complete reconstruction of an Anteosaurus skull to date, we found that overall, the nervous system of Anteosaurus was optimised and specialised for hunting swiftly and striking fast, unlike what was previously believed,” said Dr Ashley Kruger from the Natural History Museum in Stockholm, Sweden. She was also part of the study.
Benoit believes that Anteosaurus probably did its hunting at dusk and dawn, a time that is still favoured by predators today – although Anteosaurus’s world would have been very different to what it is today.
“At that time South Africa was trapped between two mountain ranges, the Cape mountains to the south and another range to the north of the country. And in between the two mountain ranges was a large flood plain that ultimately became the Karoo,” says Benoit.
“South Africa then was located much closer to the South Pole which made the weather extremely contrasted, very cold in the winters and very dry and temperate in summer.”
It is hoped in the future that CT scanning will reveal more about Anteosaurus and its world. The advantage of such scans is that fossils don’t have to be broken up to be examined. It is also becoming a bit of a fad in palaeontology.
“Now when you find a fossil, you first wonder if it will fit in the CT scanner,” laughs Benoit.
Soon Anteosaurus might be bombarded with even more powerful X-rays, that could help explain some mysteries about the animal and its kin. The plan is to take the Anteosaurus skull to the European Synchrotron Radiation Facility, in Grenoble, France.
This will possibly provide higher resolution scans.
Just this week, an international team of scientists revealed the results of a synchrotron scan of the famed hominid Little Foot. It showed that Little Foot possibly suffered two bouts of malnutrition during early childhood.
A Synchrotron scan of Anteosaurus might help scientists work out if this prehistoric carnivore was warm blooded, which would have made it even quicker and perhaps a more ruthless killer.