Dinosaur-Era life in the ancient polar oceans must have been tough, as scientists have just discovered multiple battle scars on the remains of a huge 120-million-year-old toothy marine reptile.
The discovery, which will be reported in a forthcoming issue of Acta Palaeontologica Polonica, suggests that fights over food, mates and territory were common in the oceans during a time when dinosaurs were dominant land dwellers.
Researchers made the determination after studying the fossilized remains of the marine reptile, which was an ichthyosaur. Ichthyosaurs were dolphin-resembling, fast-swimming predators that hunted down fish and squid-like animals. Adults were around 20 feet in length and possessed 100 pointed, crocodile-like teeth.
Benjamin Kear, one of the authors of the study and an Assistant Professor with the Palaeobiology Program at Uppsala University, and his colleagues spotted scars on the jaw of the fossilzed ichthyosaur as they were cleaning it.
Kear and his team believe the scars were healed bite wounds probably made by a member of the same species. The tooth marks are a good match with ichthyosaurs and do not resemble the bite of prey or other predators that were around back in the dino day.
We don’t know much about the social behavior of prehistoric animals, so this kind of finding offers important clues.
The scarred ichthyosaur was unearthed in a remote desert near the town of Marree in northern South Australia. This near-waterless place was surprisingly once part of a sea teeming with life.
When the ichthyosaur was alive, the Australian continent was still joined to Antarctica and would have been much further south than it is today. What is now arid grassland was then the bottom of a vast inland sea that experienced freezing water temperatures and even seasonal icebergs.
The ichthyosaur had to have been tough to have survived its wounds. The scientists noted that advanced healing took place, so the big reptile lived for quite a while after what must have been a pretty amazing fight.
“Pathological traces on ancient fossilised bones and teeth give unique insights into the lives and social behaviours of extinct animals,” Kear said in an Uppsala press release. “”Such finds have also rarely been reported in ichthyosaurs before.”
While humans thankfully don’t do it much, aggressive facial biting is a common social interaction observed in animals today. It’s usually done to restrain the jaws of an opponent.
source : http://news.discovery.com/dinosaurs/battle-scars-discovered-on-dinosaur-era-sea-monster.html