Scars that were found on the jaw of an ichthyosaur suggest that life was tough in the ancient polar oceans, and give an important insight into the social structure of extinct sea creatures from the time of the dinosaurs.
The jaw was found in the desert near the town of Marree in northern South Australia, and was painstakingly restored, cleaned and reassembled in a laboratory. The bite marks were found on the lower jaw, and were most likely made by a member of the same species in a fight over food, mates or territory.
“Pathological traces on ancient fossilised bones and teeth give unique insights into the lives and social behaviours of extinct animals” says Benjamin Kear, one of the authors of the study and an Assistant Professor with the Palaeobiology Programme at Uppsala University. “Such finds have also rarely been reported in ichthyosaurs before”.
Despite the bite marks, there were signs of advanced healing that suggest this particular ichthyosaur went on living for some time after the attack.
An ichthyosaur was a fast swimming predator that fed on sea life, and grew to be around six metres in length with long-snouted heads with over a hundred pointed teeth, a little like a crocodile.
The remains were found in an unlikely spot, considering that the reptile was known to be an ocean dwelling animal. So how did it end up in the middle of a desert country like Australia? The answer is simple, considering that Australia was connected to Antarctica at the time, was much further south on the planetary surface, and was much submerged by a vast inland sea.
Source: Uppsala Universitet
Image Source: Photo courtesy of Jo Bain, South Australian Museum
Ichthyosaurs were not dinosaurs, but marine reptiles.
“Ichthyosaurs thrived during much of the Mesozoic era; based on fossil evidence, they first appeared approximately 245 million years ago (mya) and disappeared about 90 million years ago, about 25 million years before the dinosaurs became extinct.”