/ 26 March 2021

Anteosaurus: Savage pre-mammalian hunter was no slowcoach

A Live Reconstruction Of Anteosaurus Attacking A Herbivorous Moschognathus
Vicious: This reconstruction of an Anteosaurus attacking a Moschognathus may be closer to the truth. Photo: Alex Bernardini (@SimplexPaleo)

The University of Witwatersrand’s evolutionary studies institute has rebranded a pre-mammalian reptile, the Anteosaurus. Previously assumed to be a sluggish, slow-moving animal, scientists now think it was indeed a savage hunter, regardless of its body size.

The institute’s Dr Julien Benoit and co-authors used X-ray imaging and 3D reconstruction for a high-resolution view of the animal’s skull, which showed that the ancient creature’s inner ear, associated with balance, was not as imagined.

Although it had a heavy-structured skeleton, scientists found that the nearly one-tonne creature’s brain and inner ear were adapted for fast motion, similar to those of Velociraptors, who are known as vicious pack hunters. 

The Anteosaurus’ nervous system was also found to be more advanced than other contemporaneous carnivores of similar size, making it possible that it would ambush, harass and run after its big or small prey.

The beast, which is believed to have roamed the African continent 260-million years ago, is known to have lived in the Guadalupian epoch on areas today known as South Africa. 

Some of its remains can be viewed at the Iziko museum of natural history in Cape Town.

According to the National Centre for Biotechnology dataset, Earth witnessed a major turning point in the mid-Permian era, in which the dataset shows a 74% to 80% loss of generic richness. South Africa was still close to the South Pole at the time.

Benoit said the large Therocephalians were Anteosaurus’ competitors at the time, but as studies stand, their brain cases have indicated that they were less likely agile and fast. 

Dinosaurs appeared on Earth around 240-million years ago and became extinct around 65-million years ago.

The Antaeus reptile was not a dinosaur but a type of dinocephalian, a pre-mammal that dominated Africa 30-million years before the dinosaur existed.

From evidence that has been found so far, the animal probably looked a little like a komodo dragon with a hippo-sized head. Large bumps and lumps above the eyes and enlarged canines gave the beast a savage look. 

It was because of these features that the Anteosaur reptile was previously presumed to be slow and living in water. 

“Other carnivores have in the past reached similar body size. It is unclear how body weight affected their hunting style. Many dinosaurs are considered agile despite huge body weight. Also, we do not have a complete skeleton so the Anteosaurus’ body weight is really just a wild guess,” said Benoit.

He said they would need to find more skeletal fragments to make a more accurate size estimate. The Brachiosaurus dinosaur was estimated to weigh 150 tonnes, but modern modelling techniques suggest a weight of 40 tonnes was more likely.

Dr Ashley Kruger, a paleontologist at the Swedish Museum of Natural History in Stockholm, said the new findings about the ancient extinct creature contradicted what they had known about it.

“In creating the most complete reconstruction of an Anteosaurus skull to date, we found that overall, the nervous system was optimised and specialised for hunting swiftly and striking fast, unlike what was previously believed,” he said.