While exploring the region around an archaeological site in the Peruvian Andes, researchers discovered a never-before-seen creature. The tiny, big-eyed marsupial — named Marmosa chachapoya — is a newly identified species of mouse opossum.
“We know very little about this species, including its natural history and distribution, and only one specimen has been collected so far,” Silvia Pavan, a biologist at Cal Poly Humboldt who led the research expedition that discovered the creature, said in a statement.
Pavan and her team were searching for a mysterious species of squirrel in Río Abiseo National Park in 2018, when they found the opossum. The little mammal, which was just 4 inches (10 centimeters) long, had reddish-brown fur and mask-like face markings.
“I realized immediately that this was something unusual,” Pavan said, in part because related species of mouse opossum are not typically found at that altitude — 8,740 feet (2,664 meters) above sea level.
The team spent years studying the opossum’s DNA and physical characteristics and comparing them to data from other mouse opossums in museum collections around the world. In June, the researchers published their detailed study in the journal American Museum Novitates, naming the marsupial Marmosa chachapoya, in honor of the ancient people who inhabited the region before the Inca Empire took over.
The ancient Chachapoya people lived in northern Peru from about A.D. 800 until the arrival of the Incas in the 1470s. Often called the “people of the cloud forest,” the Chachapoya lived in damp, rugged terrain in the eastern Andes and built their houses on summits.
More than three dozen archaeological sites have been recorded in Río Abiseo National Park, and many are associated with the Chachapoya. But the remote and difficult-to-access park was also created as a significant conservation area to protect plants and animals found nowhere else on Earth. These include the yellow-tailed woolly monkey (Lagothrix flavicauda), which was once thought to be extinct.
In addition to the new mouse opossum species, Pavan and her team discovered several other animals that they think have never been documented by scientists. These creatures, which include a semiaquatic rodent, have yet to be formally described.
The discovery of a new marsupial species is “a reminder of the critical importance of scientific exploration and conservation in areas like Río Abiseo,” Pavan said.
