The Phloeomyini tribe is also known as the ‘cloud rats’: a group of 18 giant herbivores weighing up to 2.7 kilos that live mostly in Philippine cloud forests above 1,200 meters of altitude. Now, a team of scientists from the Field Museum in Chicago has identified three new extinct species of cloud rats that provide many clues about the evolution and diversification of this group in the past.
“ The largest species were like squirrel-tailed marmots, with big bellies to ferment the plants they eat and fluffy, hairy tails. They must have been very pretty animals , ”says Larry Heaney, one of the authors of the work published in the Journal of Mammalogy . The new species, belonging to the genera Batomys, Carpomys and Crateromys , have been described from a relatively small set of fossils, some of them found in the same caves in the Philippines where the remains of Homo luzonensis were discovered a few years ago. , an extinct hominid that would have inhabited this area at least 67,000 years ago and whose presence in the region could have been related to the extinction of the giant rats.
Why did they become extinct?
“Previous studies have already shown that the Philippines is home to an extraordinary diversity of mammals, but most are small animals that live in the tropical forest,” explains Heaney. “These fossil species have been extinct relatively recently, and they show us two things. First, that in the recent past the biodiversity in this region was even greater than it is today. And second, that the two species that became extinct just a few thousand years ago were giant rodents. Their abrupt disappearance makes us suspect that they could be coveted hunting prey due to their large size ”, he reflects.
As the researchers explain, “Our records show that these giant rodents were able to survive the profound climate changes from the Ice Age to today’s humid tropics that have impacted the earth for tens of millennia. The question is, what could have caused their final extinction? “Says Philip Piper, co-author of the work and researcher at the Australian National University. Two of the species disappeared around 2,000 years ago, a significant fact according to scientists, as they coincide with the appearance, for the first time in the archaeological record, of Neolithic pottery and stone tools, and with the introduction of dogs, domestic pigs and monkeys in the Philippines. this implies that humans probably had something to do with their extinction ”, adds Armand Mijares, professor of the Archaeological Studies Program at the University of the Philippines – Diliman, who led the excavations of the Callao cave.
“Our findings suggest that future studies specifically looking for small mammal fossils can be very productive and can tell us a great deal about how environmental changes and human activities have impacted the exceptional biodiversity of the Philippines,” according to Janine Ochoa, assistant professor of archeology at the University of the Philippines – Diliman and lead author of the study. And such studies can also tell us a lot about the impact of human activities, including hunting, on biodiversity, Heaney notes. “If we want to prevent future extinctions, we must also understand what happened in the past,” he concludes.
