After a 65-year disappearance, the mysterious Horton Plains slender loris (Loris tardigradus nycticeboides) has been photographed for the first time, reports the Zoological Society of London (ZSL).

The tiny primate appeared to have gone extinct in 1939 after its Sri Lankan forest habitats were clear-cut to create tea plantations. A chance encounter in 2002 led to a massive expedition to find the animal, and after nearly 1,000 nocturnal surveys in 120 forest areas researchers have discovered that the loris was, indeed, still among the living. Not only did the team manage to photograph the animal (a loris subspecies) for the first time, they caught three of them long enough to measure them. (They're just 20 centimeters long, by the way.)

Anyway, that's the good news. The bad news is that the Horton Plains slender loris is still pretty darn rare. Researchers fear there may only be 100 or so of these animals left, which would make it one of the five most endangered primate species. They also say the number could be as low as 60—which would, indeed, make it the world's rarest primate.

This rediscovery "improves our knowledge of this species, but we need to focus our efforts on the conservation and restoration of the remaining montane forest where this species still exists," ZSL conservation biologist Craig Turner said in a prepared statement. "Currently, this accounts for less than 1 percent of the land area of Sri Lanka."

The team's work in Sri Lanka isn't done. They are studying all loris species in Sri Lanka to determine their needs as well as the threats they face.

Photo: © C. Mahanayakage, courtesy the Zoological Society of London