Giant Cloud Rat Twice the Size of a Squirrel Discovered in the Caves of the Philippines

Scientists discovered fossils of three extinct giant cloud rat species from a series of caves in the Philippines. Analysis of their bones and teeth confirmed it was the fluffy, big, bushy rat that roamed the planet from tens of thousands of years ago.

The rodents were said to be twice the size of a gray squirrel that went extinct a few thousands of years ago, with humans as one of the possible culprits.

The full findings were published in a study about other mammals featured in the March 2021 issue of the Journal in Mammology, entitled "March Mammal Madness 2021."

Giant Cloud Rats Discovered in the Philippines

Larry Heaney, the curator of mammals at the Field Museum in Chicago, said that the bigger giant cloud rats would have looked like a groundhog with a squirrel tail. These species eat plants and have great big potbellies that ferment plants that they eat, just like cows.

He added that the fossils of these giant cloud rat species show that biodiversity at that time was even greater than today, Republic reported. The fossils were found in Callao Cave, where Homo luzonensis was discovered in 2019. Some fossils were also found in Penablanca, Cagayan Province.

Some of the fossils found were even discovered in the same layer as where the Homo luzonensis were unearthed, suggesting that they must have been around 70,000 years ago.

Archaeology assistant professor Janine Ochoa from the University of the Philippines said that they had found evidence that the extinct large mammals on the island of Luzon in the Philippines for a long time. But they found no evidence of a smaller mammal.

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Remnants of the Cloudrunners

Giant cloud rats are also known as cloud runners that live in the treetops of misty mountain forests and fill the ecological role that squirrels occupy in other countries, CityAM reported.

Researchers said that the remnants of the cloud runners revealed that they were resilient and persistent creatures for at least 60,000 years before completely disappearing.

Philip Piper from the Australian National University said that records have shown that the giant cloud rat species could survive the profound climatic changes starting from the Ice Age to the current humid tropics that have affected the planet for over tens of thousands of years.

"The question is what might have caused their final extinction?" Piper asked.

Moreover, the abrupt disappearance of the cloud runners coincides with the timeline when poetry and Neolithic stone tools and dogs, domestic pigs, and monkeys were introduced to the Philippines.

Professor Armand Mijares of the archaeological studies program at the University of the Philippines, Diliman, said that scientists could not exactly pinpoint the cause of the giant rat species' extinction, but their record implies that humans likely played some role in it.

Heaney said that the abrupt disappearance of the giant cloud rats species from a few thousand years ago leaves researchers to wonder that perhaps they were big enough to be hunted and eaten by early humans.