Scientists have discovered three new species of giant cloud rats that were twice the size of a gray squirrel and roamed the planet tens of thousands of years ago.
Fossilized remains of extinct creatures have been discovered in a series of caves in the Philippines.
Based on an analysis of bones and teeth, the researchers said these giant cloud rats were fluffy and had large, bushy tails.
Rodents became extinct a few thousand years ago, suggesting the possibility that humans played a role in their extinction.
Larry Heaney, curator of mammals at the Field Museum in Chicago, said: “The bigger ones would almost look like a groundhog (woodchuck) with a squirrel tail.
“Cloud rats eat plants, and they have very big bellies that allow them to ferment the plants they eat, much like cows.
“They have big, fluffy or hairy tails. They are really very cute.
He added: “Their abrupt demise just a few thousand years ago makes us wonder if they were big enough that it would have been useful to hunt and eat them.”
Also known as cloudrunners, modern cloud rats are nocturnal rodents native to the Philippines.
They live in the treetops of misty mountain forests and fulfill an ecological role occupied by squirrels in other countries, researchers say.
Ancient fossils have been found in Callao Cave and in several smaller caves adjacent to Penablanca, a town in Cagayan province.
Callao Cave was also home to Homo luzonensis, an ancient human species that lived around 67,000 years ago.
Some of the remains of these rodent species have been found in the same layer where H. luzonensis was discovered, making it almost 70,000 years old.
Other remains are believed to be around 2,000 years old – around the time these giant rodents suddenly went extinct.
The researchers said this means these ancient giant cloud rats “were tough and persistent for at least 60,000 years.”
Philip Piper, who is based at the Australian National University, said: “Our records show that these giant rodents were able to survive the profound climate changes from the Ice Age to the present-day humid tropics that have impacted the earth for dozens. of millennia.
“The question is, what could have caused their final extinction?”
According to the researchers, one possibility is that humans played a role in their abrupt demise as the timeline coincides with the appearance of Neolithic pottery and stone tools and “when dogs, domestic pigs and possibly monkeys were introduced in the Philippines ”.
Armand Mijares, professor in the archaeological studies program at the University of the Philippines – Diliman, said: “While we cannot say for sure based on our current information, it does imply that humans have probably played a role. role in their extinction. “
The research is published in the Journal of Mammalogy.