Yuanmou Man (, ''Homo erectus yuanmouensis'') is a subspecies of ''

H. erectus ''Homo erectus'' (; meaning "upright man") is an extinct species of archaic human from the Pleistocene, with its earliest occurrence about 2 million years ago. Several human species, such as '' H. heidelbergensis'' and '' H. antecessor' ...

'' which inhabited the Yuanmou Basin in the Yunnan Province, southwestern China, roughly 1.7 million years ago. It is the first fossil evidence of humans in China, though they probably reached the region by at least 2 million years ago. Yuanmou Man is known only from two upper first

incisor Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, wher ...

s presumed to have belonged to a male, and a partial tibia presumed to have belonged to a female. The female may have stood about in life. These remains are anatomically quite similar to those contemporary early ''

Homo ''Homo'' () is the genus that emerged in the (otherwise extinct) genus '' Australopithecus'' that encompasses the extant species ''Homo sapiens'' ( modern humans), plus several extinct species classified as either ancestral to or closely relat ...

'' in Africa, namely ''

H. habilis ''Homo habilis'' ("handy man") is an extinct species of archaic human from the Early Pleistocene of East and South Africa about 2.31 million years ago to 1.65 million years ago (mya). Upon species description in 1964, ''H. habilis'' was highly c ...

'' and '' H. (e?) ergaster''. Yuanmou Man inhabited a mixed environment featuring grassland, bushland, marshland, and forest dominated by

pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden accepts ...

and

alder Alders are trees comprising the genus ''Alnus'' in the birch family Betulaceae. The genus comprises about 35 species of monoecious trees and shrubs, a few reaching a large size, distributed throughout the north temperate zone with a few sp ...

. They lived alongside chalicotheres,

deer Deer or true deer are hoofed ruminant mammals forming the family Cervidae. The two main groups of deer are the Cervinae, including the muntjac, the elk (wapiti), the red deer, and the fallow deer; and the Capreolinae, including the re ...

, the elephant ''

Stegodon ''Stegodon'' ("roofed tooth" from the Ancient Greek words , , 'to cover', + , , 'tooth' because of the distinctive ridges on the animal's molars) is an extinct genus of proboscidean, related to elephants. It was originally assigned to the fami ...

'', rhinos,

cattle Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult ma ...

, pigs, and the giant short-faced hyaena. The site currently sits at an elevation of . They manufactured simple cores, flakes,

choppers Chopper may refer to: Arts and entertainment * ''Chopper'' (comics), a horror comic book mini-series * ''Chopper'' (film), a 2000 Australian film by and about Mark "Chopper" Read * Chopper (''Judge Dredd''), a character in British comics anth ...

, pointed tools, and scrapers which paralleled the technology of their African contemporaries.

Taxonomy

Discovery

On May 1, 1965, geologist Qian Fang recovered two

archaic human A number of varieties of '' Homo'' are grouped into the broad category of archaic humans in the period that precedes and is contemporary to the emergence of the earliest early modern humans (''Homo sapiens'') around 300 ka. Omo-Kibish I (Omo I) f ...

upper first

s (catalogue number V1519) from fossiliferous deposits of the Yuanmou Basin near Shangnabang village, Yuanmou County, Yunnan Province, China. When they were formally described in 1973, they were determined to have belonged to a young male. Qian's field team was funded by the Chinese Academy of Geosciences. The Institute of Vertebrate Paleontology and Paleoanthropology funded further excavation of the site, and reported 16 stone tools, of which six were found ''

in situ ''In situ'' (; often not italicized in English) is a Latin phrase that translates literally to "on site" or "in position." It can mean "locally", "on site", "on the premises", or "in place" to describe where an event takes place and is used in ...

'' and 10 nearby. The Yuanmou Basin sits just to the southeast of the

Tibetan Plateau The Tibetan Plateau (, also known as the Qinghai–Tibet Plateau or the Qing–Zang Plateau () or as the Himalayan Plateau in India, is a vast elevated plateau located at the intersection of Central, South and East Asia covering most of the ...

, and is the lowest basin on the central

Yunnan–Guizhou Plateau The Yunnan–Guizhou Plateau or Yungui Plateau () is a highland region located in southwest China. The region is primarily spread over the provinces of Yunnan and Guizhou. In the southwest, the Yungui is a true plateau with relatively flatter ...

at an elevation of . The Yuanmou Formation is divided into four

members Member may refer to: * Military jury, referred to as "Members" in military jargon * Element (mathematics), an object that belongs to a mathematical set * In object-oriented programming, a member of a class ** Field (computer science), entries in ...

and 28 layers. The human teeth were discovered in the

silt Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension with water. Silt usually has a floury feel ...

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay par ...

and sandy conglomerates of Member 4 (the uppermost member) near the bottom of layer 25. In December 1984, a field team dispatched by the

Beijing Natural History Museum The Beijing Museum of Natural History (BMNH; ) is located at 126 Tian Qiao Nan Street, Dongcheng District, Beijing, 100050, and is the most popular natural history museum in China.tibial shaft in a layer just overlying layer 25 in Member 4. The tibia was described in 1991, and was determined to belong to a young female ''H. e. yuanmouensis''.

Age

The Yuanmou Formation has been identified as a fossil-bearing site since the 1920s, and palaeontological work on the area suggest a

Lower Pleistocene The Early Pleistocene is an unofficial sub-epoch in the international geologic timescale in chronostratigraphy, being the earliest division of the Pleistocene Epoch within the ongoing Quaternary Period. It is currently estimated to span the time ...

age. Because the formation is faulted (several rock masses have been displaced), biostratigraphy (dating an area based on animal remains) of the human-bearing layer is impossible. In 1976, Li Pu and colleagues palaeomagnetically dated the incisors to the Gilsa geomagnetic polarity event (when the Earth's

magnetic polarity A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nicke ...

reversed for a short interval) roughly 1.7 million years ago. In 1977, with a much larger sample size, Cheng Guoliang and colleagues instead placed the area during the Olduvai subchron, and dated it to 1.64–1.63 million years ago. In 1979, Li Renwei and Lin Daxing measured the alloisoleucine/isoleucine protein ratio in animal bones and produced a date of 0.8 million years ago for the Yuanmou Man. In 1983, Liu Dongsheng and Ding Menglin — using palaeomagnetism, biostratigraphy, and

lithostratigraphy Lithostratigraphy is a sub-discipline of stratigraphy, the geological science associated with the study of strata or rock layers. Major focuses include geochronology, comparative geology, and petrology. In general, strata are primarily igneous ...

— reported a date of 0.6–0.5 million years ago during the

Middle Pleistocene The Chibanian, widely known by its previous designation of Middle Pleistocene, is an age in the international geologic timescale or a stage in chronostratigraphy, being a division of the Pleistocene Epoch within the ongoing Quaternary Period. Th ...

, despite the animal remains pointing to an older date. In 1988, Q. Z. Liang agreed with Cheng on dating it to the Olduvai subchron. In 1991, Qian and Guo Xing Zhou came to the same conclusion as Liang. In 1998, R. Grün and colleagues, using

electron spin resonance dating Electron spin resonance dating, or ESR dating, is a technique used to date materials which radiocarbon dating cannot, including minerals ( e.g., carbonates, silicates, sulphates), biological materials (e.g., tooth enamel), archaeological materials ...

on 14 horse and rhino teeth, calculated an interval of 1.6–1.1 million years ago. In 2002, Masayuki Hyodo and colleagues, using palaeomagnetism, reported a date of 0.7 million years ago near the Matuyama–Brunhes geomagnetic boundary during the Middle Pleistocene. Later that year, the boundary was re-dated to 0.79–0.78 million years ago by geophysicist Brad Singer and colleagues. In 2003, Ri Xiang Zhu and colleagues made note of the inconsistency among previous palaeomagnetic studies, and in 2008 palaeomagnetically dated it to roughly 1.7 million years ago. They believed Middle Pleistocene dates were probably caused by too small a sample size. The tibia was probably found somewhere in layers 25–28, and by Zhu's calculations would date to 1.7–1.4 million years ago. The date of 1.7 million years ago is widely cited. This makes the Yuanmou Man the earliest fossil evidence of humans in China, and roughly contemporaneous with the oldest humans in Southeast Asia. It was part of a major expansion of ''H. erectus'' across Asia, the species extending from 40°N in Xiaochangliang to 7°S in

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mos ...

, and inhabiting temperate grassland to tropical woodland. The Yuanmou Man is only slightly younger than the Dmanisi hominins from the

Caucasus The Caucasus () or Caucasia (), is a region between the Black Sea and the Caspian Sea, mainly comprising Armenia, Azerbaijan, Georgia (country), Georgia, and parts of Southern Russia. The Caucasus Mountains, including the Greater Caucasus range ...

, 1.77–1.75 million years old, who are the oldest fossil evidence of human emigration out of Africa. These dates could therefore mean that humans spread rather rapidly across the Old World, over a period of less than 70,000 years. Yuanmou Man could also indicate humans dispersed from south to north across China, but there are too few other well-constrained early Chinese sites to test this hypothesis. Humans likely already settled in China at earliest 2.12 million years ago evidenced by stone tools recovered from the

Loess Plateau The Chinese Loess Plateau, or simply the Loess Plateau, is a plateau in north-central China formed of loess, a clastic silt-like sediment formed by the accumulation of wind-blown dust. It is located southeast of the Gobi Desert and is surrounde ...

in northwestern China.

Classification

The teeth were formally described in 1973 by Chinese palaeoanthropologist Hu Chengzhi, who identified it as a new subspecies of '' Homo erectus'', distinct from and much more archaic than the Middle Pleistocene

Peking Man Peking Man (''Homo erectus pekinensis'') is a subspecies of '' H. erectus'' which inhabited the Zhoukoudian Cave of northern China during the Middle Pleistocene. The first fossil, a tooth, was discovered in 1921, and the Zhoukoudian Cave has s ...

, ''H. ("Sinanthropus") e. pekinensis'', from Beijing. He named it ''H. ("S.") e. yuanmouensis'', and believed it represents an early stage in the evolution of Chinese ''H. erectus''. In 1985, Chinese palaeoanthropologist Wu Rukang said that few authors in the field recognise ''H. e. yuanmouensis'' as valid, with most favouring there having been only one subspecies of ''H. erectus'' which inhabited China. However, in 2011, Indonesian palaeoanthropologist Yahdi Zaim and colleagues, based on dental comparisons, concluded that the

Sangiran Sangiran is an archaeological excavation site in Java in Indonesia. According to a UNESCO report (1995) "Sangiran is recognized by scientists to be one of the most important sites in the world for studying fossil man, ranking alongside Zhoukoud ...

''H. erectus''—which had colonised Java by 1.6 million years ago—had descended from a different dispersal event than the Peking Man who had colonised China by 780,000 years ago. The Sangiran teeth were notably more reminiscent of the early ''

'' from Africa than those of the Peking Man. This would mean that ''H. erectus'' dispersed across East Asia multiple times.

Anatomy

For the teeth, only the left and right first incisors are preserved for the Yuanmou Man. The left incisor measures in breadth and in width, and the right incisor and . The incisors are overall

robust Robustness is the property of being strong and healthy in constitution. When it is transposed into a system, it refers to the ability of tolerating perturbations that might affect the system’s functional body. In the same line ''robustness'' ca ...

. They notably flare out in breadth from bottom to top. The labial (lip) side is mostly flat with the exception of some grooves and depressions, and the base is somewhat convex like that of the Peking Man. The lingual (tongue) side caves in like that of the Peking Man, but has a defined ridge running down the middle like ''H. (e?) ergaster'' and ''H. habilis''. The cross section at the neck of the tooth (at the gum line) is nearly elliptical. Similar anatomy is also exhibited in Late Pleistocene archaic human specimens from

Xujiayao Xujiayao, located in the Nihewan Basin in China, is an early Late Pleistocene paleoanthropological site famous for its archaic hominin fossils. Location Xujiayao is located on the west bank of the Liyi River, a tributary of the Sanggan River. Xuji ...

, China; and

Neanderthal Neanderthals (, also ''Homo neanderthalensis'' and erroneously ''Homo sapiens neanderthalensis''), also written as Neandertals, are an extinct species or subspecies of archaic humans who lived in Eurasia until about 40,000 years ago. While the ...

s from Krapina, Croatia. The tibia is a long mid-shaft fragment. It is gracile and laterally (on the sides) flattened. The anterior (front) aspect is round and obtuse, and has a weak S-curve. The interosseous crest (which separates the muscles on the back of the leg from those of the front of the leg) is shallow. On the posterior (back) aspect, there is a ridge running down the middle, developed attachment (where the muscle used to attach to the bone) for the

flexor digitorum longus muscle The flexor digitorum longus muscle is situated on the tibial side of the leg. At its origin it is thin and pointed, but it gradually increases in size as it descends. It serves to flex the second, third, fourth, and fifth toes. Structure The fle ...

(which flexes the toes), and a defined

soleal line The soleal line, also known as the popliteal line (in older texts), is a prominent ridge on the posterior surface of the tibia. It is the site of many muscle origins and insertions, such as those of popliteus muscle, soleus muscle, flexor digitor ...

. It is somewhat similar to tibiae assigned to ''H. habilis''. Like other ''H. erectus'', the tibia is quite thick, constricting the

medullary cavity The medullary cavity (''medulla'', innermost part) is the central cavity of bone shafts where red bone marrow and/or yellow bone marrow ( adipose tissue) is stored; hence, the medullary cavity is also known as the marrow cavity. Located in the m ...

where the bone marrow is stored. At the probable midpoint of the shaft, the circumference is , the breadth from left to right is , and from front to back is . The individual may have stood roughly .

Culture

Palaeohabitat

A total of 35 other animals have been reported from layer 25. The mammals are: the chalicothere '' Nestoritherium''; the deer '' Cervocerus ultimus'', '' Procapreolus stenosis'', '' Paracervulus attenuatus'', '' Rusa yunnanensis'', '' Cervus stehlini'', '' Muntiacus lacustris'', ''M. nanus'',

gazelle A gazelle is one of many antelope species in the genus ''Gazella'' . This article also deals with the seven species included in two further genera, '' Eudorcas'' and '' Nanger'', which were formerly considered subgenera of ''Gazella''. A third ...

, and

chital The chital or cheetal (''Axis axis''; ), also known as the spotted deer, chital deer, and axis deer, is a deer species native to the Indian subcontinent. It was first described and given a binomial name by German naturalist Johann Christian Po ...

;

; pigs; the elephant ''

''; rhino; the giant short-faced hyaena ''Pachycrocuta brevirostris licenti'';

pika A pika ( or ; archaically spelled pica) is a small, mountain-dwelling mammal found in Asia and North America. With short limbs, very round body, an even coat of fur, and no external tail, they resemble their close relative, the rabbit, but wi ...

; and small rodents. Various

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

turtle Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked t ...

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can ...

s, and plants were also found. Fossil pollen deposits on the Yuanmou teeth and artefacts can largely be assigned to herbaceous plants,

, and

. Altogether, they suggest Yuanmou Man inhabited a mixed environment featuring open grassland, bushland, forest, marshland, and freshwater, not unlike what is suggested for the Dmanisi hominins.

Technology

In 1973, three retouched tools were found within of the incisors, two of them in a layer in elevation below the incisors, and an additional one about above the incisors. Three similar tools were recovered at the surface of the Shangnabang site. Within , cores, flakes,

, pointed tools, and scrapers were found,} totaling 16 tools. They were made of

quartz Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical ...

and quartzite probably gathered from the nearby river. Most were modified with direct hammering (using a hammerstone to flake off pieces), but a few were modified with the bipolar technique (smashing the core with the hammerstone, creating several flakes). The tools feature simple conchoidal fracture, not unlike contemporary

Oldowan The Oldowan (or Mode I) was a widespread stone tool archaeological industry (style) in prehistory. These early tools were simple, usually made with one or a few flakes chipped off with another stone. Oldowan tools were used during the Lower ...

tools from Africa. In 1985, Chinese palaeoanthropologist Jia Lanpo described two probably burnt mammal bones as well as considerable charcoal remnants from Yuanmou. He suggested this could represent extremely early fire usage by humans. These bones and similarly aged burnt remnants from various parts of the world are now considered to be the products of natural wildfires. It is rather doubtful that even Peking Man was using fire.

References

External links

Human Timeline (Interactive)
– Smithsonian,

National Museum of Natural History The National Museum of Natural History is a natural history museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C., United States. It has free admission and is open 364 days a year. In 2021, with 7 ...

(August 2016). {{Taxonbar, from=Q1195256 Archaeological sites in China Archaeology of China Homo erectus fossils Pleistocene Prehistoric China Chuxiong Yi Autonomous Prefecture Major National Historical and Cultural Sites in Yunnan 1965 archaeological discoveries 1965 in China Subspecies