KNM-ER 732 A

KNM-ER 732 A
Date of Discovery: 1970
Discovered by: Richard Leakey and H. Mutua
Age: About 1.7 million years old
Fossil Name: KNM-ER 732 A
Location of Discovery: Koobi Fora, Kenya

KNM-ER 732, a partial cranium of a female Paranthropus boisei has many characteristic P. boisei features. Most notable is the forward placed root of the zygomatic arch, resulting in a wide flat face. This skull has a cranial capacity of 500 cubic centimeters, nearly identical to the 510 cubic centimeters of presumed male P. boisei KNM-ER 406.Yet the skull shows less robust facial features than KNM-ER 406; the face is less massive overall, and it lacks a sagittal crest.  From this scientists conclude that KNM-ER 732 represents a female of the Parathropus boisei species. Thus, this fossil provides clues as to the nature of sexual dimorphism in this early human species.

Paranthropus boisei