Chimpanzee, often shortened to chimp, is the common name for the two extant species of apes in the genus Pan. The better known chimpanzee is Pan troglodytes, the Common Chimpanzee, living primarily in West, and Central Africa. Its cousin, the Bonobo or "Pygmy Chimpanzee" as it is known archaically, Pan paniscus, is found in the forests of the Democratic Republic of the Congo. The Congo River forms the boundary between the two species. Chimpanzees are members of the Hominidae family, along with gorillas, humans, and orangutans, and the two chimpanzee species are the closest living relatives to humans.