The first remains of Gigantopithecus, two third molar teeth, were identified in a drugstore by anthropologist Ralph von Koenigswald in 1935, who subsequently described the ape.

[4] Gigantopithecus was once argued to be a hominin, a member of the human line, but it is now thought to be closely allied with orangutans, classified in the subfamily Ponginae.

Gigantopithecus has traditionally been restored as a massive, gorilla-like ape, potentially 200–300 kg (440–660 pounds) when alive, but the paucity of remains make total size estimates highly speculative.

Gigantopithecus had the thickest enamel by absolute measure of any ape, up to 6 mm (1⁄4 inch) in some areas, though this is only fairly thick when tooth size is taken into account.

It primarily lived in subtropical to tropical forest, and went extinct about 300,000 years ago likely because of the retreat of preferred habitat due to climate change, and potentially archaic human activity.

Gigantopithecus has become popular in cryptozoology circles as the identity of the Tibetan yeti or the American bigfoot, apelike creatures in local folklore.

[1] The specific name blacki is in honour of Canadian palaeoanthropologist Davidson Black, who had studied human evolution in China and had died the previous year.

Von Koenigswald, working for the Dutch East Indies Mineralogical Survey on Java, had found the teeth in a drugstore in Hong Kong where they were being sold as "dragon bones" to be used in traditional Chinese medicine.

An isolated canine from Thẩm Khuyên Cave, Vietnam, and a fourth premolar from Pha Bong, Thailand, could possibly be assigned to Gigantopithecus, though these could also represent the extinct orangutan Pongo weidenreichi.

[1] In 1939, South African palaeontologist Robert Broom hypothesised that it was closely allied with Australopithecus and the last common ancestor of humans and other apes.

However, there are few similar traits (synapomorphies) linking Gigantopithecus and orangutans due to fragmentary remains, with the main morphological argument being its close affinities to Sivapithecus, which is better established as a pongine based on skull features.

[13] Cladogram according to Zhang and Harrison, 2017:[4] Hylobates (gibbons) Oreopithecus Ouranopithecus Dryopithecus Gorilla (gorillas) Pan (chimpanzees) Australopithecus and Homo (humans) Gigantopithecus Lufengpithecus Ankarapithecus Sivapithecus Pongo (orangutans) In 1969, an 8.6 million year old mandible from the Sivalik Hills in northern India was classified as "G. bilaspurensis" by palaeontologists Elwyn L. Simons and Shiv Raj Kumar Chopra [de], who believed it was the ancestor of G.

In 1970, Simons and American palaeontologist Peter Ettel approximated a height of almost 2.7 m (9 feet) and a weight of up to 270 kg (600 pounds), which is about 40% heavier than the average male gorilla.

[4] The canines, due to a lack of honing facets (which keep them sharp) and their overall stoutness, have been suggested to have functioned like premolars and molars (cheek teeth).

[4] The molar-like premolars, large molars, and long rooted cheeked teeth could point to chewing, crushing, and grinding of bulky and fibrous materials.

[21] Similarly, oxygen isotope analysis suggests Gigantopithecus consumed more low-lying plants such as stems, roots, and grasses than orangutans.

[23] In 1975, American palaeoanthropologist Tim D. White drew similarities between the jaws and dentition of Gigantopithecus and those of the giant panda, and suggested they both occupied the same niche as bamboo specialists.

[4] Gigantopithecus remains are generally found in what were subtropical evergreen broadleaf forest in South China, except in Hainan which featured a tropical rainforest.

Carbon and oxygen isotope analysis of Early Pleistocene enamel suggests Gigantopithecus inhabited dense, humid, closed-canopy forest.

Queque Cave featured a mixed deciduous and evergreen forest dominated by birch, oak, and chinkapin, as well as several low-lying herbs and ferns.

[4] The "Gigantopithecus fauna", one of the most important mammalian faunal groups of the Early Pleistocene of southern China, includes tropical or subtropical forest species.

The early stage is characterised by more ancient Neogene animals such as the gomphotheriid proboscidean (relative of elephants) Sinomastodon, the chalicothere Hesperotherium, the suid Hippopotamodon, the tragulid Dorcabune  [it], and the deer Cervavitus.

The late stage features more typical Middle Pleistocene animals such as the panda Ailuropoda baconi and the stegodontid proboscidean Stegodon.

[34] Longgudong Cave may have represented a transitional zone between the Palaearctic and Oriental realms, featuring, alongside the typical Gigantopithecus fauna, more boreal animals such as hedgehogs, hyenas, horses, the bovid Leptobos, and pikas.

[35] The former correlates with a cooling trend marked by intensifying seasonality and monsoon strength in the region, which led to the encroachment of rainforests by open grasslands.

[36][22] Because Gigantopithecus teeth dating to this time show evidence of dietary shifts and chronic nutritional stress, it may have been less successful at adapting to these environmental stressors compared to contemporary great apes — namely Pongo weidenreichi and Homo — which could have led to its extinction.

[36][38] Human activity in southern China is known as early as 800,000 years ago but does not become prevalent until after the extinction of Gigantopithecus, so it is unclear if pressures such as competition over resources or overhunting were factors.

This began in 1960 with zoologist Wladimir Tschernezky, briefly describing in the journal Nature a 1951 photograph of alleged yeti tracks taken by Himalayan mountaineers Michael Ward and Eric Shipton.