The species classification of
archaic humans during the
Middle Pleistocene has always been a controversial topic, commonly referred to as "the muddle in the middle". In mainland East Asia, the early Middle Pleistocene was home to
Homo erectus — best exemplified regionally by the
Peking Man — but as the
age continues, the anatomy of archaic human fossils becomes highly variable, with traits reminiscent of the earlier
H. erectus but also
H. heidelbergensis or modern humans. Historically, they have been characterized as hybrids of the indigenous
H. erectus and newcomers from the west, an undescribed species, or multiple different species; and classified as
H. heidelbergensis, archaic
H. sapiens, or simply Middle Pleistocene
Homo. Genetic data also identifies an enigmatic population referred to as the "
Denisovans" which were apparently dispersed across East Asia and
interbred with modern humans and
Neanderthals. In 2024, Chinese palaeoanthropologist Xiujie Wu and Korean-American anthropologist Christopher Bae erected a new species,
H. juluensis (derived from the
Mandarin Chinese 巨颅/巨顱, meaning "large-headed"), to house the Denisovans (specifically the
Xiahe mandible),
Penghu 1, and remains from
Xujiayao and
Xuchang. They made the Xujiayao material the
holotype and Xuchang the
paratype. Japanese anthropologist Yousuke Kaifu and American paleoanthropologist Sheela Athreya suggested that the
Hexian material may be a descendant of Xuchang and belong to the same population. Though they agreed that Hexian, Penghu 1, and Xiahe group well together, they questioned the inclusion of the Denisovans, since only the
mandibular ramus (the part of the jaw that goes up to connect with the skull) is preserved in the Xujiayao remains, but only the mandibular body is preserved by the Xiahe mandible, making direct anatomical comparisons with the holotype material impossible. ==Description==