Homo sapiens idaltu, also called Herto Man, is the name given to a number of early modern human fossils found in 1997 in Herto Bouri, Ethiopia. They date to around 160,000 years ago. Palaeoanthropologists determined that the skeletal finds belong to an extinct group of Homo sapiens who lived in Pleistocene Africa. The subspecies H. s. idaltu falls under the umbrella of Anatomically modern humans. The recognition of H. s. idaltu as a valid subspecies of the anatomically modern human lineage would justify the description of contemporary humans with the subspecies name H. s. sapiens, though physical anthropologistChris Stringer does not consider idaltu distinct enough within H. sapiens to warrant its own subspecies designation, and instead classifies it simply as anatomically modern H. sapiens. Palaeoanthropologist Tim D. White and others consider the fossils represent the probable immediate ancestors of anatomically modern humans.
Discovery
The fossilized remains of Homo sapiens idaltu were discovered at Herto Bouri near the Middle Awash site of Ethiopia's Afar Triangle in 1997 by Tim White, Giday WoldeGabriel and Berhane Asfaw, but were first unveiled in 2003. Herto Bouri is a region of Ethiopia under volcanic layers. According to radioisotope dating, the layers are between 154,000 and 160,000 years old. Three well preserved crania are accounted for, the best preserved being from an adult male having a brain capacity of. The other crania include another partial adult male and a six-year-old child.
The Herto remains differ from those of chronologically later forms of early Homo sapiens; their morphology has features that show resemblances to African fossils, such as huge and robust skulls, yet have a globular shape of the brain-case and the facial features typical of H. sapiens. These specimens are regarded by some as an extinct Homo sapiens subspecies that may have been direct ancestors of modern Homo sapiens sapiens which, according to the "recent African origin " or "out of Africa" model, developed shortly after this period in Eastern Africa. "The many morphological features shared by the Herto crania and AMHS, to the exclusion of Neanderthals, provide additional fossildata excluding Neanderthals from a significant contribution to the ancestry of modern humans."
Dating
A 2005 potassium-argon dating of volcanic tuff associated with the Omo remains showed them to date from around 195,000 years ago. This makes the fossils the earliest known remains of anatomically modern humans, older than the idaltu specimens.
Contrary opinion
Anthropologist Chris Stringer argued in a 2003 article in the journal Nature that "the skulls might not be distinctive enough to warrant a new subspecies name".
