Anthropology: Shelf Two

Research Guide for topics related to the study of anthropology.

Gorilla and Orangutan

On Shelf #2: Gorillas (Gorilla gorilla) are the largest of the great apes – a group that includes chimpanzees, bonobos, gorillas and orangutans. Except for the last, all live in forested parts of Africa and are closely related to humans. Where the African great apes are separated from us by about 6 to 7 million years, Orangutans are more distant cousins, separated from us by perhaps as much as 15 million years. Orangutans are the only great apes found naturally outside of Africa. They live on the Indonesian islands of Sumatra and Borneo – each island serving as the habitat of two distinct species (Pongo pygmaeus on Borneo and Pongo abelli on Sumatra.)

•  Note the very large canine teeth of the gorilla and orangutan on display. Both are of male individuals.  While these teeth can inflict severe damage if these individuals choose to bite, their main use is probably in threat displays against other males of their own species. Males of both species are substantially larger than the females and males compete fiercely for sexual access to and control of females.

•  Also note the large bony ridge that runs front to back over the top of the skull. That bony structure called the sagittal crest serves as the anchor point for very large muscles that power the massive lower jaw.  Compare the sagittal crest here to those on the skulls displayed on shelf #1 in display case #2.

* See article at the bottom of the page for more information!

Image: Gorilla skull

 

Image: Gorilla side view (skull)

Image: Orangutan skull

Image: Orangutan skull, side view

 

Gorillas - Princeton Encyclopedia of Mammals