Abstract: Davidson Black initially identified the third skull (Skull E) from the 1929 excavations of Zhoukoudian as an adolescent or early adult female. Later, after preparation that revealed additional details of the bones, Black modified his opinion suggesting the Skull E was an early adolescent male, equivalent in age to a modem twelve-year-old. Weidenreich agreed with Black, but assigned a slightly younger age of eight to nine years to the specimen. He based this conclusion on four points, including the presence of: a cleft in the tympanic bone, a lacrimal groove, small frontal torus, and small glenoid fossa. Since then, many paleoanthropologists have been puzzled by the identification of the Skull E.
In this paper, this skull is compared with other Homo erectus skulls, especially the skull from Nanjing, an adult female. The comparison shows that Skull E shares features in common with the Nanjing skull, including smaller cranial dimensions, relatively small supraorbital torus, and faint muscle makings. Meanwhile, the cleft in llie tympanic bone, lacrimal groove, glenoid fossa, frontal sinus and thickness of cranial wall are not indictors that show the skull to be immature ormale. It is noteworthy that the Skull 12 from Zhoukoudian, a mature one, exhibits open sutures without any hint of closure, as the state of the sutures of kull 3.In view of the above considerations, this skull represents an adult female.

Key words: Homo erectus; Zhoukoudian; Sex; Age; Adult female