It’s tiny and cute, with a mottled back, a long tail and bright, curious eyes. The Mura saddleback tamarin was just discovered in a remote area of the Brazilian Amazon, but already, its future is in question thanks to the ever-growing presence of humans in its habitat.

The rabbit-sized primate weighs just 7.5 ounces and stands a mere 9 inches tall. A distant relative of humans, this little tamarin is named for the Mura Indians who occupy the same stretch of land in the Purus and Madeira river basins. Scientists still don’t know how many there are in the area.

Construction projects have pushed further and further into jungle, endangering many thousands of species that have already been discovered as well as untold numbers that we still don’t know about. Still, says Avecita Chicchón, director of WCS's Latin American and Caribbean Program, finding a new mammal is rare, and the discovery of the Mura saddleback tamarin is a stark reminder of what’s at stake.

Chicchón points at several new development projects in the area including two hydroelectric dams, saying “These are a significant threat to wildlife that are not even documented.”