Bonobo
Related most closely to the chimpanzee, the bonobo is one of the great apes. It was only identified by humans in 1933 due to the fact that it inhabits the densest and remotest parts of the Congo rainforest. According to ZooSociety.org, "some anthropologists consider the bonobo to be the best living prototype for the common ancestor of humans." However, chimpanzees are a closer genetic match to humans. More than any other African great ape, bonobos spend a lot of time in trees eating fruits, leaves and stem piths. Females give birth approximately once every five years; babies are completely dependent for four years. They are currently listed as endangered, and scientists do not have an accurate idea of their numbers in the wild, according to the Zoological Society of Milwaukee.