The rat, dubbed Paucidentomys vermidax, is a type of shrew rat that lives onÂ Sulawesi Island in Indonesia. It’s the first known rodent to lack cheek teeth.
The rat is missing all of its molar teeth, and instead only has incisors. While the rat’s “smile” is hard to see (and maybe there’s not much to smile about in the tough rodent world), it looks buck-toothed, due to the presence of just these larger front teeth.
Jacob Esselstyn of McMaster University and colleagues point out that all other known rodents — and there are some 2300 species — retain a lot of teeth. The choppers are needed to munch on all of the diverse things that rodents eat, such as seeds, grasses and even other smaller animals.