A direct ancestor emerges
In 1997, a team of paleoanthropologists led by Tim White discovered the remains of early modern humans near the village of Herto in the Middle Awash region of Ethiopia. The fossils were found in the Upper Herto Member of the Bouri Formation, a layer of sediment sandwiched between volcanic deposits. This geological context was perfect for dating. Using the argon-argon dating method on the volcanic rock, scientists established the age of the skulls at between 154,000 and 160,000 years old.
The discovery included three well-preserved crania: one nearly complete adult male (designated BOU-VP-16/1), a partial second adult, and one from a child estimated to be six or seven years old. These individuals possess features that are distinctly modern, such as a high cranial vault and a flat face, placing them firmly within our own species, Homo sapiens. However, they also retain some more robust, archaic traits, like a slightly larger and longer skull, which led their discoverers to classify them as a new subspecies: Homo sapiens idaltu. The word idaltu means "elder" in the local Afar language. The male skull, BOU-VP-16/1, has a cranial capacity of approximately 1,450 cubic centimeters, which is slightly larger than the average for humans today.