A unique species of near-toothless rat that lives off earthworms and does not chew or gnaw has been discovered in Indonesia.
The shrew-like animal with a long, pointed snout was described online in this week’s British journal Biology Letters.
Paucidentomys vermidax, which translates loosely to “few-toothed rat” and “worm eater,” is the only rodent out of more than 2,200 known species that does not have molars and instead has bicuspid upper incisors, the article said.
Two rats were found in the mountainous rain forest of southern Sulawesi Island last year on Mount Latimojong and 100km northwest on Mount Gandangdewata.
Since it lacks cheek teeth, the rat sucks in earthworms and slices them with its incisors before spitting out the pieces and then slurping bites down whole, said co-author of the article Anang Achmadi, from Indonesia’s Museum Zoologicum Bogoriense.
The researchers said the discovery is important because it shows how rodents, which are known for biting and chewing, were forced to evolve to survive in Sulawesi’s environment.
“What defines rodents is their capacity to gnaw with their ever-growing incisors, which are worn down to form chisels,” said co-author Kevin Rowe, senior curator of mammals at Museum Victoria in Melbourne, Australia.
“It’s a remarkable evolution that a trait that’s been so successful [and] has allowed rodents to chew into everything from seeds to felling trees to eating our garbage and chewing their way into our house, this species has given up on that capacity in the pursuit of its lifestyle, which appedars to include eating earthworms,” Rowe added.
The new rat demonstrates the island’s unique biodiversity despite human threats from illegal logging and mining, Achmadi said.