The face of Olduvai Hominid 12.

Facial remains of Homo erectus are rare and their scarcity hinders our understanding of the variability and relationships in this taxon. Previously undescribed fragments of the peri-orbital region and unidentified matches between fragments of Olduvai Hominid 12 (OH 12) enhance comparison of the African H. erectus hypodigm. The newly reconstructed upper face and maxilla of OH 12 is most similar in size and shape to that of KNM-ER 3733, despite being as much as one million years younger than the Koobi Fora hominin. However, the posterior vault and mastoid region of OH 12 are most similar to OH 9. This combination of morphology suggests that the relationship between the Olduvai and Koobi Fora portions of the H. erectus hypodigm requires reconsideration.