Image: OH 9 Homo ergaster skull angled view
Cast of OH 9 partial skull discovered in 1960 by Louis Leakey at Olduvai, Tanzania. Dated to about 1.2-1.5 million years old.
- Carl Bento
- © Australian Museum
This skull shares more features with Asian Homo erectus than with other African Homo ergaster remains and is closest in size and morphology to skull Sangiran 17. This implies that either Homo erectus migrated back into Africa from Asia or that all the Homo ergaster and Homo erectus specimens should be classified as one highly variable species, rather than two.