Herto Man refers to human remains (Homo sapiens) discovered in 1997 from the Upper Herto member of the Bouri Formation in the Afar Triangle, Ethiopia. The remains have been dated as between 154,000 and 160,000 years old. The discovery of Herto Man was especially significant at the time, falling within a long gap in the fossil record between 300 and 100 thousand years ago and representing the oldest dated H. sapiens remains then described.
In the original description paper, these 12 (at minimum) individuals were described as falling just outside the umbrella of "anatomically modern human". Thus, Herto Man was classified into a new subspecies as "Homo sapiens idaltu" (Afar: Idaltu "elder"). It supposedly represented a transitional morph between the more archaic "H. (s.?) rhodesiensis and H. s. sapiens (that is, a stage in a chronospecies). Subsequent researchers have rejected this classification. The validity of such subspecies is difficult to justify because of the vague definitions of "species" and "subspecies", especially when discussing a chronospecies, as the exact end-morphology and start-morphology of the ancestor and descendant species are inherently unresolvable.
Herto Man produced many stone tools which can fit into the vaguely defined "Transitional Acheulean", the long-lasting cultural tradition with both characteristically Acheulean (made by archaic humans) and Middle Stone Age (made by modern humans) tools. They seem to have been butchering mainly hippo, but also bovines, in a lakeside environment. The three most complete skulls (one a 6- to 7-year-old child) bear manmade cut marks and other alterations, which could be evidence of mortuary practices like excarnation.
Fossils of Herto Man were first recovered in 1997 from the Upper Herto Member of the Bouri Formation in the Middle Awash site of the Afar Triangle, Ethiopia. The materials are: BOU-VP-16/1, a nearly complete skull missing the left skullcap; BOU-VP-16/2, skull fragments; BOU-VP-16/3, a parietal bone fragment; BOU-VP-16/4, a parietal fragment; BOU-VP-16/5, a nearly complete skull of a 6- or 7-year old; BOU-VP-16/6, a right upper molar; BOU-VP-16/7, a parietal fragment; BOU-VP-16/18, parietal fragments; BOU-VP-16/42, an upper premolar; and BOU-VP-16/43, a parietal fragment.[1] Further excavation has yielded a total of 12 individuals.[2]
This region of the world is famous for yielding a series of ancient human and hominin species stretching as far back as 6 million years.[1] In 2003, using argon–argon dating, the Upper Herto Member was dated to 160 to 154 thousand years ago.[3] The Herto Man was, thus, a major fossil find, as, at the time, there was a significant gap in the human fossil record between 300 and 100 thousand years ago, obfuscating the evolution of "Homo (sapiens?) rhodesiensis" into H. s. sapiens.[1]