1. Homo ergaster
A lesser known Homo

2. Homo ergaster’s relationship to Homo erectus
1.9 million years ago Homo ergaster emerged in Africa. Some scientists call this species Homo erectus but many researchers now say that there where enough differences between the early Homo erectus and the latter ones in Europe and Asia that the early one should be called by a different name.

3. Pieces of Homo ergaster
This is what Homo ergaster’s head looks like with out any skin.

4. More piece’s of Homo ergaster
This is the jaw bone of Homo ergaster and his head.

5. Homo ergaster physical differences from Homo erectus
Homo ergaster did not have a depression just behind the brow ridge unlike Homo erectus. Homo ergaster also had thinner bones in the skull then Homo erectus.

6. Homo ergaster’s advance in technology
1.6 million years ago Homo ergaster started making large cutting tools like cleavers and hand axes out of stone. This advance is known as the Achulean stone tool industry.

7. Turkana boy
Is a almost complete skeleton of an 11 or 12 year old Homo ergaster boy. He dates back to 1.6 million years ago around the time of the Achulean stone tool industry when Homo ergaster first started make big stone cutting tools.

8. Turkana boy
This is Turkana boy’s skeleton.

9. Turkana boy
The reason why many believe that Turkana boy is a Homo ergaster and not a Homo erectus is he doesn’t have the depression behind the jaw that a Homo erectus would have and he doesn’t seem to have had the larger brain Homo erectus had.

10. Homo ergaster conclusion
Homo ergaster maybe a lesser known Homo and it may just be the primitive version of Homo erectus but it differs enough from Homo erectus that it deserves its own name in the evolutionary chain.

11. My Sources http://anthropology.si.edu/HumanOrigins/ha/erg.html