Dragon Man (archaic human)

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https://en.wikipedia.org/wiki/Homo_longi

Homo longi
Temporal range: Middle Pleistocene 0.146  Ma
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HBSM2018-000018(A) cranium. Scale bar = 50mm
HBSM2018-000018(A) cranium
Scientific classification edit
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Suborder: Haplorhini
Infraorder: Simiiformes
Family: Hominidae
Subfamily: Homininae
Tribe: Hominini
Genus: Homo
Species:
H. longi
Binomial name
Homo longi
Ji et al., 2021

Dragon Man (Homo longi) is an extinct species of archaic human identified from a nearly complete skull in Harbin, on the Northeast China Plain, dating to at minimum 146,000 years ago during the Middle Pleistocene. The skull was discovered in 1933 along an under-construction bridge of Manchukuo National Railway and finally brought to paleoanthropologists in 2018. Those scholars considered modern humans to be more closely related to H. longi than to the European Neanderthals, which may force a revision of the current scientific consensus.

H. longi is broadly anatomically similar to other Middle Pleistocene Chinese specimens, and potentially represents the enigmatic Denisovans, though this is unconfirmed. Like other archaic humans, the skull is low and long, with massively inflated brow ridges, wide eye sockets, and a large mouth. The skull is the longest ever found from any human species. Like modern humans, the face is rather flat, but the nose was rather large. The brain volume was 1,420 cc, within the range of modern humans and Neanderthals.

The Harbin individual inhabited a cold, steppeland environment alongside the woolly mammoth, giant deer, Przewalski's horse, elk, buffalo, and brown bear.

Taxonomy

Etymology

Dragon Man (archaic human) is located in China
Harbin
Harbin
Xiahe
Xiahe
Denisova Cave
Denisova Cave
Locations of the Harbin skull and the Denisovan remains, which Ni et al., 2021, hypothesised represent the same species [1]

The specific name for H. longi is derived from the geographic name Longjiang (literally "Dragon River"), a term commonly used for the Chinese province Heilongjiang. [2]

Discovery

The skull was discovered in 1933 along Dongjiang Bridge [ zh] (pictured top), then under construction by Manchukuo National Railway.

A local laborer found a nearly complete skull at the riverbank of Songhua River in 1933 when he was building the Dongjiang Bridge [ zh] in Harbin (at the time part of Manchukuo) for the Japanese-aligned Manchukuo National Railway. Recognizing its importance, likely as a result of public interest in anthropology recently generated by the Peking Man in 1929, he hid it from the Manchukuo authorities in an abandoned well. After the Soviet defeat of Manchukuo, he concealed his former Manchukuo National Railway employment from the Nationalist and later the Communist authorities. [1]

Before his death, the third generation of his family learned of the skull, and reclaimed it in 2018. Later that year, Chinese paleoanthropologist Ji Qiang persuaded the family to donate it to the Hebei GEO University for study, where it has since been stored. Its catalogue number is HBSM2018-000018(A). [1]

Age

Owing to the skull's tumultuous history, its exact provenance, and thus its stratigraphic context and age, has been difficult to determine. [3] [4] In 2021, Chinese geologist Shao Qingfeng and colleagues performed non-destructive x-ray fluorescence, rare-earth element, and strontium isotope analyses on the skull and various other mammalian fossils unearthed around Dongjiang Bridge, and determined that all the various fossils from the vicinity were probably deposited at around the same time, lived in the same region, and originate 12 m (39 ft) below the surface of Dongjian, correlating to 30 m (98 ft) within the Upper Huangshan Formation (constrained to 309 to 138 thousand years ago). [3]

Direct uranium–thorium dating of various points on the skull yielded a wide range of dates, from 62 to 296 thousand years ago, likely a result of uranium leaching. They statistically determined the most likely minimum age is 146,000 years old, but a more exact value is difficult to determine, given that the exact provenance is unidentifiable. Nonetheless, the skull is well-constrained to the late Middle Pleistocene, roughly contemporaneous with other Chinese specimens from Xiahe, Jinniushan, Dali, and Hualong Cave. [3]

Classification

Recent human family tree

Neanderthals

Homo antecessor

Jinniushan

Hualong

Dali

Xiahe

Harbin

Modern humans

According to Ni et al. 2021 [1] (note, Xiahe and Denisovans are most closely related to Neanderthals according to nDNA and ancient protein analyses. [5])

In two simultaneously published papers, Ji and colleagues declared the Harbin skull to represent a new species they dubbed Homo longi. The Harbin skull is quite similar to the Dali skull, and when the Dali skull was discovered in 1978, it was given a new nomen H. sapiens daliensis by its discoverer Wu Xinzhi who shortly abandoned it. Consequently, should the Middle Pleistocene Asian humans represent a single unique species, the nomen H. daliensis would take priority. Though they recommended resurrecting H. daliensis, they argued H. longi is sufficiently distinct, and allocated only the Dali and Hualong remains to H. daliensis (thus, they claim at least two human species inhabiting late Middle Pleistocene China). [2] One of the authors, Chris Stringer, stated that he would have preferred assigning the Harbin skull to the H. daliensis lineage. [6]

Instead, based on the conspicuously massive size of the molars, they suggested H. longi is most closely allied to and possibly the same species as the Xiahe mandible from Tibet, [2] which has been grouped with the enigmatic Denisovans, an archaic human lineage apparently dispersed across East Asia during the Middle and Late Pleistocene currently identifiable from only a genetic signature. The Xiahe mandible is also anatomically similar to specimens from Xujiayao and Penghu. [7] Ji, Ni and colleagues further contend that Middle Pleistocene Asian specimens are more closely related to modern humans (H. sapiens) than the European Neanderthals, [2] [1] though nuclear DNA and ancient protein analyses place the Xiahe mandible and Denisovans more closely to Neanderthals than modern humans. [5] [8]

Anatomy

H. longi is characterized by a low and long skull, receding forehead, exorbitantly wide upper face, a large nasal opening equating to an enlarged nose (possibly an adaptation to the cold air), large and square eye sockets, inflated and thick brow ridges (supraorbital torus), flat cheekbones ( zygomatic bone), a wide palate and big tooth sockets (equating to a large mouth), and a broad base of the skull. [2] The Harbin skull measures 221.3 mm × 164.1 mm (8.7 in × 6.5 in) in maximum length x breadth, with a naso- occipital length of 212.9 mm (8.4 in), making it the longest archaic human skull to date. [1] For comparison, the dimensions of a modern human skull averages 176 mm × 145 mm (6.9 in × 5.7 in) for men and 171 mm × 140 mm (6.7 in × 5.5 in) for women. [9] The Harbin skull also has the longest brow ridge at 145.7 mm (5.74 in). [1]

The Harbin skull is similar to the contemporaneous Dali skull (reconstruction above). [1]

H. longi had a massive brain at roughly 1,420 cc, above the range of all known human species except modern humans and Neanderthals. Nonetheless, post-orbital constriction (constriction of the braincase just behind the eyes, equating to the frontal lobe, absent in modern humans) is more developed in H. longi than Neanderthals, though not as much as more ancient human species. [2] Overall, the braincase retains an array of archaic features, though the occipital bone at the back of the skull has a weakly defined torus which lacks a protuberance at the midpoint, unlike most other archaic humans. Unlike the Dali and Hualong Cave skulls, there is no sagittal keel running across the midline. Unlike modern humans or Neanderthals, the parietal bones on the top of the head do not significantly expand or protrude. [1]

Despite the face being so wide, it was rather flat (reduced mid-facial prognathism), and recalls the condition exhibited in modern humans, the far more ancient H. antecessor, and other Middle Pleistocene Chinese specimens. Nonetheless, the tooth sockets for the incisors were angled outward (alveolar prognathism). The H. longi skull's mosaic morphology of archaic and derived traits converges with some of the earliest specimens assigned to H. sapiens from Africa, notably Jebel Irhoud and Eliye Springs. Because the original describers judged the Harbin skull to be closely allied with the Xiahe mandible, they believed H. longi lacked a chin, like other archaic humans, but the specimen's lower jaw was not recovered. [1] The only preserved tooth, the upper left second molar, is enormous, with a length x breadth (mesiodistal x labiolingual) of 13.6 mm × 16.6 mm (0.54 in × 0.65 in), comparable to the Denisovan molar recovered from Denisova Cave. The Harbin molar is oval-shaped and badly worn, nearly flat. [1] In contrast, the average of dimensions of a sample 40 modern human males was 10.2 mm × 11.8 mm (0.40 in × 0.46 in). [10]

The describers believed the Harbin skull represents a male less than 50 years old, judging the suture closures, and the degree of tooth wearing. They speculated H. longi had perhaps medium-dark to medium-light skin, dark hair, and dark eye color based on reconstructed genetic sequences from Neanderthals, Denisovans, and early modern humans. [1]

Pathology

The left parietal features shallow indents around the bregma, possibly from a healed injury. The second left upper molar does not seem to have been in contact with the third molar, which either means the third molar was small (creating a gap) or absent in this individual. [1]

Paleoenvironment

Due to the Pleistocene glaciation (the Ice Ages), the Earth continually swings from frigid glacial periods to warmer interglacials. The period from 300 to 130 thousand years ago spans the Penultimate Glacial Period, and the permafrost zone may have stretched south far past Harbin (though indicators of permafrost activity are lacking so far back in time). [11] Similarly, the Northeast China Plain during the late Middle Pleistocene was home to the Mammuthus Coelodonta Fauna, an assemblage of animals adapted for a cold steppe, most notably the woolly mammoth and the woolly rhinoceros. [12] In addition to the woolly mammoth, the Dongjiang Bridge [ zh] locality also features the giant deer Sinomegaceros ordosianus, Przewalski's horse, elk, the buffalo Bubalus wansjock, and the brown bear. [3]

See also

References

  1. ^ a b c d e f g h i j k l m Ni, X.; Ji, Q.; Wu, W.; et al. (2021). "Massive cranium from Harbin in northeastern China establishes a new Middle Pleistocene human lineage". Innovation. doi: 10.1016/j.xinn.2021.100130 (inactive 2021-06-26).CS1 maint: DOI inactive as of June 2021 ( link)
  2. ^ a b c d e f Ji, Qiang; Wu, Wensheng; Ji, Yannan; Li, Qiang; Ni, Xijun (2021-06-25). "Late Middle Pleistocene Harbin cranium represents a new Homo species". The Innovation. 0. doi: 10.1016/j.xinn.2021.100132 (inactive 2021-06-25). ISSN  2666-6758.CS1 maint: DOI inactive as of June 2021 ( link)
  3. ^ a b c d Shao, Q.; Ge, J.; Ji, Q.; et al. (2021). "Geochemical provenancing and direct dating of the Harbin archaic human cranium". Innovation. doi: 10.1016/j.xinn.2021.100131 (inactive 2021-06-26).CS1 maint: DOI inactive as of June 2021 ( link)
  4. ^ Gibbons, A. (2021). "Stunning 'Dragon Man' skull may be an elusive Denisovan—or a new species of human". Science. doi: 10.1126/science.abk1691 (inactive 2021-06-26).CS1 maint: DOI inactive as of June 2021 ( link)
  5. ^ a b Chen, F.; Welker, F.; Shen, C.-C.; et al. (2019). "A late Middle Pleistocene Denisovan mandible from the Tibetan Plateau" (PDF). Nature. 569 (7756): 409–412. Bibcode: 2019Natur.569..409C. doi: 10.1038/s41586-019-1139-x. PMID  31043746. S2CID  141503768.
  6. ^ Sample, Ian (25 Jun 2021). "Massive human head in Chinese well forces scientists to rethink evolution". The Guardian. Retrieved 28 June 2021.
  7. ^ Chen, F.; Welker, F.; Shen, C.-C.; et al. (2019). "A late Middle Pleistocene Denisovan mandible from the Tibetan Plateau" (PDF). Nature. 569 (7756): 409–412. Bibcode: 2019Natur.569..409C. doi: 10.1038/s41586-019-1139-x. PMID  31043746. S2CID  141503768.
  8. ^ Reich, D.; Green, R. E.; Kircher, M.; et al. (2010). "Genetic history of an archaic hominin group from Denisova Cave in Siberia" (PDF). Nature. 468 (7327): 1053–60. Bibcode: 2010Natur.468.1053R. doi: 10.1038/nature09710. hdl: 10230/25596. PMC  4306417. PMID  21179161.
  9. ^ Li, H.; Ruan, J.; Xie, Z.; Wang, H.; Liu, W. (2007). "Investigation of the critical geometric characteristics of living human skulls utilising medical image analysis techniques". International Journal of Vehicle Safety. 2 (4): 345–367. doi: 10.1504/IJVS.2007.016747.
  10. ^ Bjorndal, A. M.; Henderson, W. G.; Skidmore, A. E.; Kellner, F. H. (1974). "Anatomic measurements of human teeth extracted from males between the ages of 17 and 21 years". Oral Surgery, Oral Medicine, Oral Pathology. 38 (5): 795. doi: 10.1016/0030-4220(74)90402-2. PMID  4530970.
  11. ^ Jin, H.; Vendehnberhg, J.; Luo, D.; et al. (2020). "Quaternary Permafrost in China: Framework and Discussions". Quaternary. 3 (4): 32. doi: 10.3390/quat3040032.
  12. ^ Kahlke, R.-D. (2014). "The origin of Eurasian Mammoth Faunas (MammuthusCoelodonta Faunal Complex)". Quaternary Science Reviews. 96: 32–49. doi: 10.1016/j.quascirev.2013.01.01 (inactive 2021-06-30).CS1 maint: DOI inactive as of June 2021 ( link)

External links