The great ape first scientifically described in 1929 from a skull collected in the Congo was the bonobo.
The bonobo, Pan paniscus, had been mistaken for a young or unusual common chimpanzee. German anatomist Ernst Schwarz examined a skull held at the museum in Tervuren, Belgium, and recognized that it represented a distinct form. The specimen and associated skin had been collected in the Congo basin; the museum received them in 1927, while Schwarz’s scientific publication appeared in 1929.
Schwarz initially classified the animal as a subspecies of chimpanzee, Pan satyrus paniscus. American anatomist Harold Coolidge later provided a fuller anatomical study and helped establish the bonobo as a separate species in 1933. The older name “pygmy chimpanzee” is now generally avoided because bonobos are not merely undersized chimpanzees.
Bonobos and common chimpanzees are the two living species of Pan and are both humanity’s closest living relatives. Bonobos occur naturally only in forests south of the Congo River in the Democratic Republic of the Congo. Their different social behavior, anatomy, and range support their status as a separate species.