In a paper published November 2017, an international team of scientists described a new species of orangutan.The Tapanuli orangutan, the eighth known great ape, is distinct from its Sumatran and Bornean cousins in several key ways.The species is also highly threatened, with plans to develop a hydroelectric dam in its only known habitat raising alarm among conservationists.This is the first in a two-part series about the discovery of the Tapanuli orangutan. Part Two will be published Feb. 20. When an international team of scientists published their description of a new ape species, the Tapanuli orangutan (Pongo tapanuliensis), in the journal Current Biology in November 2017, it marked the culmination of years of painstaking research. It also highlighted the urgent need to protect this rare ape and save its rapidly shrinking upland forest habitat. The new orangutan species, named for the Tapanuli region in Indonesia’s North Sumatra province, has a population of roughly 800 individuals and is found only in a 1,100-square-kilometer (425-square-mile) patch of the Batang Toru forest ecosystem, an area currently being cleared for a hydroelectric dam and associated infrastructure. Geneticists, morphologists and behavioral scientists talked to Mongabay about how their research led to the discovery of this new species of great ape.