Lost to the outside world for a generation—and feared extinct—a small deer-like species with tiny fangs has been photographed tiptoeing through a dry lowland forest in southern Vietnam. The last known scientific recording of the animal, known as the silver-backed chevrotain (Tragulus versicolor), dates to 1990, when a hunter killed one and donated the specimen to scientists.

"It's a really cool species, and we'd long hoped to find proof they were still around," says Andrew Tilker, a biologist specializing in Southeast Asian wildlife at Global Wildlife Conservation, an environmental group, and a doctoral student with the Leibniz Institute for Zoo and Wildlife Research in Germany.

The silver-backed chevrotain, also known as the Vietnamese mouse-deer, is about the size of a large