Homo heidelbergensis is a species of archaic human from the Middle Pleistocene of Europe and Africa, as well as potentially Asia depending on the taxonomic convention used. The species-level classification of Homo during the Middle Pleistocene is controversial, called the "muddle in the middle", owing to the wide anatomical range of variation that populations exhibited during this time. H. heidelbergensis has been regarded as either the last common ancestor of modern humans, Neanderthals, and Denisovans; or as a completely separate lineage.
H. heidelbergensis was described by German anthropologist Otto Schoetensack in 1908 based on a jawbone, Mauer 1, from a sand pit near the village of Mauer — 10 km (6.2 mi) southeast of Heidelberg. It was the oldest identified human fossil in Europe, and Schoetensack described it as an antediluvian race (before the Great Flood) which would eventually evolve into living Europeans. By the mid-20th century, all archaic human taxa were lumped as subspecies of either H. erectus or H. sapiens, with the former evolving into the latter without any coexistence. The species was usually lumped as H. e. heidelbergensis. While its utility was complicated by its definition on a jawbone (which is rarely ever found, and otherwise bears few diagnostic features) British physical anthropologist Chris Stringer revived the species in 1983, redefining it as a Euro-African ancestor of modern humans and Neanderthals using namely Kabwe 1, Petralona 1, Bodo, and Arago. These skulls are united mainly by their supraorbital torus (brow ridge) anatomy.
