3. Bipedalism was very likely an adaptation to living in this kind of environment—it provided advantages for survival.
6. The earliest known species of robust australopithecine--it lived about 2.5 million years ago. So far, this species has been found only in East Africa. Since it had a smaller brain than the other robust species and it was early, it is thought to be a transitional form from one of the gracile species that came before. It had a very large sagittal crest.
8. A South African robust species of early hominins that lived about 2.0-1.4 million years ago.
10. The earliest known australopithecine species. They lived 4.2-3.9 million years ago in East Africa.
11. The term for the bones of the hip region.
12. A species of australopithecine that lived about 3.3-2.5 million years ago in South Africa. Skeletally, they were less ape- like than earlier species of australopithecines but were still usually small and light in frame. This may have been the last australopithecine species.
13. A term applied to the non-robust australopithecines and the earliest humans. It means graceful, slender, and delicate and is used to describe the body characteristics (especially bones) of these species.
14. The genus of all human species.

1. The genus of early hominids that was most likely the immediate ancestor of humans.
2. Meave Leakey discovered this 3.5- 3.2 million year old hominin near Lake Turkana in 2001. She suggested that it will displace Australopithecus afarensis as the progenitor of humans. The name of this species means "flat- faced man from Kenya".
4. Two species of late australopithecines are the leading contenders for being the immediate ancestor of early Homo. One of these is Australopithecus africanus. What is the other?
5. A species of early australopithecines that lived 3.7- 3.0 million years ago in East Africa. Skeletally, they were still somewhat transitional from early Pliocene apes.
7. The bony arch extending horizontally on either side of the face just below the eyes on primates and many other vertebrates. The major jaw muscles pass under these arches on their way up to the temporal areas of the skull for attachment.
9. A super-robust East African species of australopithecine that lived about 2.4-1.4 million years ago. They were more massive and beefy-looking than Australopithecus robustus. While they were only a few inches taller, they averaged 20 pounds heavier.