Scientists have unmasked a new species of primate—a type of slow loris called Nycticebus kayan.

Small, nocturnal animals native to South and Southeast Asia, slow lorises are poorly understood, mostly due to their slow movements and nighttime activity.

But scientists are able to distinguish slow loris species using the primates' distinctive face masks, or markings. So a team recently examined several museum specimens and photographs of the slow loris species Nycticebus menagenis of Borneo (map).

Differences in face markings revealed that N. menagenis had incorrectly included three additional species of slow loris—two of which were previously classified as subspecies and N. kayan, which is completely new to science. (Also see "'Extinct,' Pop-Eyed Primate Photographed for First Time.")

N. kayan has "really unique, striking eye patches that go below the chin—none of the [other] species exhibit that trait in Borneo," said study co-author Rachel Munds of the University of Missouri in Columbia.

Beware the Slow Loris

Like all slow lorises, N. kayan has a toxic bite—one of the few mammals that do, noted Munds, who worked with Susan Ford of Southern Illinois University in Carbondale and Anna Nekaris of Oxford Brookes University in the U.K.

To access its poison, a slow loris rubs its hands under glands near its armpits—"kind of like Molly [Shannon] from Saturday Night Live," Munds quipped. Then the animal applies the poison to its teeth, and the resulting bite can put a person or predator into potentially fatal anaphylactic shock.

Slow lorises might also use their poison to catch prey or even protect their babies, Munds said. For instance, there's evidence that mothers spread the poison on their babies when they leave them to go foraging—deterring potential predators.

But slow lorises haven't been able to fend off hunters feeding a demand for the primates in the illegal pet trade. The appetite for these pets has led N. menagenis to be listed as vulnerable by the International Union for Conservation of Nature, and Munds suspects the new species will follow suit. (See pictures of Asia's wildlife trade in National Geographic magazine.)

But knowing more about Borneo's slow lorises, Munds said, will help conservationists save these "fascinating little creatures."