Fossils indicate giant rats co-existed with humans until quite recently.
Rats are indisputably one of the most pesky creatures alive. They are notorious house pests, breed faster than rabbits, and transmit deadly diseases including viral hemorrhagic fever, Weil’s disease, and Q fever. But despite the maddening qualities of rats, we can all be grateful for one thing — they are so much smaller than the Rodents of Unusual Size from The Princess Bride.
But rats weren’t always such a manageable size. Archaeologists at the Australian National University recently unearthed the bones of rats that were 10 times the size of modern rats. Based on their estimates, the largest of these giant rodents would have weighed in at about 5 kilograms (11 pounds) or approximately the size of a small dog.
The bones, which belonged to the largest rats to ever walk the Earth, were uncovered on a recent expedition to East Timor where researchers have been trying to understand the migration patterns of our human ancestors.
"We're trying to find the earliest human records as well as what was there before humans arrived," explains Dr Julien Louys of the ANU School of Culture, History and Language, one of the project leaders.
What is most interesting about their find is that the arrival of humans was not what caused the animals to go extinct. Humans actually lived alongside giant rats in East Timor from 46,000 years ago — when humans arrived on the island — until about 1,000 years ago when the animals went extinct.
According to analyses of the fossils, it is likely that giant rat was on the menu for our ancestors. Researchers report cut and burn marks on the bones that could only have been made by human activities.
But was that why they went extinct? Were the massive rodents too delicious for their own good or was something else afoot? Because the hunters and the huntees co-existed for thousands of years, archaeologists suspect that changes to the ecosystem were the cause of the extinction, not overhunting.
“The reason we think they became extinct is because that was when metal tools started to be introduced in Timor, people could start to clear forests at a much larger scale," guesses Louys.
This finding was part of a larger research effort to understand how early humans migrated through the islands of Southeast Asia and how their arrival changed the natural ecosystems. Their research is highly relevant to conservation efforts today as we try to predict the consequences of the changes we are making to modern ecosystems.
Based on materials provided by the Australian National University.