A one-million-year-old human pubic symphysis

Here, we describe an intact, undistorted, adult pubic symphysis (UA-466) from the w1 Ma Uadi Aalad site in the Buia sedimentary basin of the Eritrean Danakil. The left pubis was discovered in November 2003 from surface collections near where a cranium, two isolated teeth, and two right innominate fragments were previously found from a single outcrop. UA-466 comes from the same sedimentological level as these other remains, exhibits similar fossilization and coloration, and is embedded in a similar black matrix. However, UA-466 was found on the surface about 15 meters from the other remains. At present, it cannot be determined if any of the bones belong to the same individual. The magnetostratigraphic record from Buia indicates that the Homo-bearing layer is w1 Ma, falling near the top of the Jaramillo normal subchron. Fission-track dating of an intercalated tephra confirms this chronology, which is further corroborated by the mammalian biochronology. Associated Oldowan and Acheulean stone tool assemblages are also widespread at Uadi Aalad and surrounding areas.