Gigantopithecus

Credit: Jesusgamarra on DeviantArt.

*Gigantopithecus* is an extinct genus of ape that lived in Southern China, The Indian Subcontinent (Mainly Nepal), Indonesia, Thailand, Java and Vietnam during the Early through Late Pleistocene.

## History

*Gigantopithecus* was named by Ralph von Koenigswald (1935) based on two third lower molars, which were noted to be massive. The second molar is 20 x 22 millimeters (0.79 x 0.87 inches). The name "*blacki*" was coined after Davidson Black, who had died the year before. Von Koenigswald was working the the Dutch East Indied Meneralogical Survey on Java, when he found the "dragon bones" in a Hong Kong drugstore as traditional medicine. He determined the teeth were from Guangdong or Guangxi after purchasing more in 1939. However, due to internment by Japanese soldiers in World War II, he could not name the specimens until 1952. The original set are housed at the University of Utrecht.

A survey by a team lead by Pei Wenzhong (1955) and tasked by the Chinese Institute of Vertebrate Palaeontology and Palaeoanthropology  (IVPP) to find the original *Gigantopithecus* locality. From Giangdong and Guangxi, they recovered 47 teeth and several shipments of "dragon bones". From a cave later named "*Gigantopithecus* Cave, the team also discovered (in 1956) the first in situ remains: a third molar and premolar. The cave is located in Niusui Mountian, Gaungxi. In the same year, farmer Xiuhuai Qin found more teeth and  a mandible in his field. IVPP surveys from 1957-1963 excavated the locality to find two mandibles and 1000+ teeth.

Across 16 sites, *Gigantopithecus* are known from south China. Northernmost, Longgupo and Longgudong (south of the Yangtze River), ad the southernmost on Hainan Island in the South China Sea. Additionally, a single canine from Thẩm Khuyên Cave, Vietnam and a fourth premolar from Pha Bong, Thailand could be from this ape, with others concluding they are *Pongo weidenreichi*. Two fragmented mandibles with the last two molars from Semono, Central Java, Indonesia described in 2016 may also be *Gigantopithecus*. The oldest remains, the 2-million-year-old Baikong Cave and the youngest at 380-310,000 years are reported from Hei Cave. A fourth mandible was confirmed in 2014 from Yanliang, Central China. The mandible has many gnawing marks caused by rodents. The remains likely accumulated in caves from porcupines, who gnaw on bones to obtain their nutrients to grow quills. Porcupines are reported to drag remains into underground burrows to consume them entirely, except for the teeth crowns capped by enamel. This could explain why teeth are found in large quantity, and how other remains are nonexistent. A full m2 with roots and a fragmented distal crown is the only specimen from the Late Pleistocene. It is known from Langchang Cave, Vietnam and is likely a relict population during a transitional faunal phase.

## Description

Since only jaw elements are known, and molars do not often correlate with weight, it is hard to determine how large these apes were. The same issues persist in post-canine megadontian hominins, who have short bodies, but massive molars with thick enamel. Weidenreich (1946) hypothesizes *Gigantopithecus* was twice the size of a male gorilla. Pei (1957) estimates a height of 3.7 meters (12 feet), with Elwyn Simons and Peter Ettel (1970) did the same, with an estimated height of almost 2.7 meters (9 feet) and a weight of 270 kilograms (600 pounds). The latter estimates are 42% heavier than a male gorilla. In 1979, Alfred E. Johnson Jr. uses the dimensions from a gorilla and applied it to *Gigantopithecus*, churning out a femur length of ~54.4 centimeters (1 feet, 9 inches) and a humerus length of 62.7 centimeters (2 feet, 1 inch), ~20-25% longer than in gorillas. Yingqi Zhang  and Terry Harrison (2017) suggest a body mass of 200-300 kilograms (440-660 pounds), with the two stating the estimate was probably an overestimate, and that it was impossible to gain reliable statistics without more complete material. On average, the maximum length for the upper canines in males and females are 21.1 millimeters (0.83 inches) for the former and 15.4 millimeters (0.61 inches) for the latter. As Mandible III is 40% larger than Mandible I, III is a presumed male and I a female. Such would imply sexual dimorphism, a high degree of which is only surpassed in gorilla canine size, and is surpassed by no other ape in mandibular disparity.

*Gigantopithecus* had a dental formula of 2.1.2.32.1.2.3, it had two incisors, a canine, two premolars and three molars one one half of the jaw, for both jaws. The canines have a lack of honing facets and are stout, making scientists think that they functioned more as premolars and molars. Since the molars were enlarged the incisors were not. At the lingual face, wearing on the incisors shows signs of an underbite. Such anatomy in the mandible suggests lateral excursion while chewing. Incisors were tipped by extremely long roots, ~2x  the tooth crown in the visible tooth. All teeth were packed closely.

The upper third premolar is an average 20.3 x 15.2 millimeters (0.8 x 0.6 inches) in surface area, the fourth premolar 15.2-16.4 millimeters (0.6-0.65 inches), the first and second molar (difficult to distinguish) are 19.8 x 17.5 millimeters (0.78 x 0.69 inches) and the third molar is 20.3 x 17.3 millimeters (0.8 x 0.68 inches). The lower third premolar is 15.1 × 20.3 millimeters (0.59 × 0.80 inches), the fourth premolar is 13.7 × 20.3 millimeters (0.54 × 0.80 inches), The first and second are 18.1 × 20.8 millimeters (0.71 × 0.82 inches) and the third is 16.9 × 19.6 millimeters (0.67 × 0.77 inches). *Gigantopithecus* has the largest molars of any primate, with the teeth known to have increased over time. It had premolars with high crowns, with the lower set having two roots and the upper three. Lower molars have low crowns, are long and narrow, with a midline waist and low bulbous cusps with rounded crests. The waist was more defined than in the lower molars.

The enamel is the thickest of any ape, at average of 2.5-2.9 millimeters (0.098-0.114 inches) in three molars, and 6 millimeters (0.24 inches on the lingual cusps in an upper molar. Some compare this to hominins like *Paranthropus* (known as 'robust' for their thick enamel, among other features), but *Gigantopithecus* overlaps with many other extinct and extant apes. Like orangutans (and possibly all pongines, and unlike African apes), *Gigantopithecus* molars have a tabular grinding surface than had even enamel and short dentine horns. Molars are the most hypsodont in any ape.

## Paleobiology

### Diet

    *Gigantopithecus* is thought to have been a herbivore, with Carbon-13 isotope analysis suggesting the ape ate C3 plants such as fruits, leaves and other forest plants, a generalistic diet. It had a robust mandible capable of resisting high strain to chew through tough or hard plants. Although, similar anatomy is sometimes seen in folivorous or granivorous apes. A generalist diet is indicated by a pitting pattern more similar to chimpanzees than to orangutans.

Molar-like premolars, molars and long-rooted cheek teeth point towards the chewing, crushing and grinding of large fibrous plants. The thick enamel suggests the food was abrasive, such as dirt particles gathered on low-lying food. Oxygen isotope analysis shows *Gigantopithecus* consumed low plants like stems, roots and grasses more than orangutans. The consumption of tubers is also suggested by dental calculus, with commonplace savannah C4 plants (grasses). In 1990, several opal phytoliths and four teeth from *Gigantopithecus* Cave were found to have came from grasses, with most of the phytoliths appearing like fig family fruits. This indicates fruits were common in the diet, at least in this population, of *Gigantopithecus*.

Teeth from Hejiang Cave 400-320,000 years old show differences from the Early Pleistocene remains. This could show that this population, that lived near the time of extinction, were specialized to a changing climate and different food. These teeth have a more crenulated enamel surface due to secondary crests emanating from the paracone, the protocone, and the other side closer to the medial, with sharper and more major crests.

Pei (1957) hypothesizes *Gigantopithecus* was a predator who dragged prey into caves based on the remains of ungulates in a cave (from a "seemingly inaccessible mountain"), with the hypothesis becoming unfavourable due to traits pointing towards herbivory. Tim D. White (1975) saw *Gigantopithecus* and the giant panda had similar traits, concluding they both could have been bamboo specialists. Other researchers reached similar conclusions, but thicker enamel and hypsodonty may suggest other uses.

### Ontogeny

It was estimated a third molar from a *Gigantopithecus* would have taken, based on the assumption it takes 600-800 days for the enamel and cusps to form (quite long), 4 years to form, which is within the upper range of humans and chimpanzees. Like other fossil primates, the enamel formation rate near the enamel-dentine junction was estimated at 4 micrometers per day, as seen in the baby teeth of extant apes. Protein sequencing in enamel show alpha-2-HS-glycoprotein (AHSG), which is important for bone and dentine mineralization in modern apes. Because this was found in enamel, rather than dentine, AHSG may have been an additional component that facilitated biomineralization in enamel during a period of long amelogenesis.

### Paleopathology

At a cavity rate of 11% in molars, *Gigantopithecus* likely relied on fruit. Molars from *Gigantopithecus* Cave show pitting enamel hypoplasia, which can be caused by malnutrition during growth. This could have been caused by periodic food shortages, but other factors can cause this. PA1601-1 (Yanliang Cave) indicates tooth-loss, specifically in the right second molar before the neighbouring third molar erupted. The latter grew slanted. This implies the individual survived for a long time, despite chewing disabilities.

### Intraspecific Confrontations

Sexual dimorphism was high, which could suggest intense male-male competition. Although, the upper canines project slightly farther than the cheek teeth, so canine display was likely not very relevant in intraspecific confrontations, contrary to other apes.

## Classification

Von Koenigswald (1935) classifies *Gigantopithecus* as a close taxon to *Sivapithecus*. Robert Broom (1939), however, places the ape as related to *Australopithecus*, being the last common ancestor to humans and other apes. Franz Weidenreich (1946) describes the specimens as a human ancestor, "*Gigantanthropus*", as a 'gigantic phase' in human evolution. He relates the teeth to *Pithecanthropus* (*Homo erectus*) and anatomically modern humans, considering the lineage to go from *Gigantopithecus*, to *Meganthropus* (once *Homo erectus palaeojavanicus*, or *Homo palaeojavanicus*) and finally the dubious *Pithecanthropus*. In 1952, von Koenigswald considered *Gigantopithecus* as a hominin, believed an offshoot rather than a direct descendant to humans. Such a topic was debated for the following three decades, until African hominins were discovered. This placed human origins in Africa, rather than Asia. A mandible from Sivalik Hills found in 1969 was classified as a new species, *G. bilaspurensis*, believed to be an ancestor of *G. blacki*. Said fossil bears resemblance to a molar from *Dryopithecus giganteus*. In 1950, the latter was moved into the new genus *Indopithecus* by von Koenigswald, then changed to *Gigantopithecus giganteus* by Frederick Szalay and Eric Delson in 1979. The genus was resurrected by David W. Cameron in 2003. Today, *Gigantopithecus bilaspurensis* is a synonym of *Indopithecus giganteus*.

    *Gigantopithecus* is now considered a pongine closely related to *Sivapithecus* and *Indopithecus*. The closest living ancestor is *Pongo*, however, few synapomorphies link the two due to fragmentary remains, with the main argument being the close affiliation with *Sivapithecus*. The latter is an established pongine due to skull features. Yingqi Zhang and Terry Harrison (2017) suggest *Gigantopithecus* is related to *Lufengpithecus*. Peptide dentine sequencing from 2019 of a *Gigantopithecus* molar from Chuifeng Cave confirms a close relation with orangutans, with the assumption a constant mutation rate, share a common ancestor ~12-10 million years ago. This would have been a part of the Miocene radiation in apes. The same paper calculates ponginae diverges 26-17.7 million years ago. Zhang and Harrison (2017):

Semedo 3417 and 3418 are two enigmatic mandible fragments discovered in 2014 and described in 2016. In phylogenetic testing, they recover closest to *G. blacki* in two separate clades, which suggests the need for further taxonomic refinement.

## Paleoecology

*Gigantopithecus* is known from subtropical evergreen broadleaf forests from Southern China, minus Hainan, which features a rainforest biome. Carbon and oxygen isotope analysis from enamel shows that it preferred dense, humid and closed-canopy forests. Areas like Queque Cave were mixed deciduous and evergreen, with the majority being oak, birch and chinapin, with low herbs and ferns.

Of all the faunal groups, the "*Gigantopithecus* fauna" represents one of the most important mammalian groups from Early Pleistocene South Chine. This includes tropical and subtropical forested species. This group has three distinct stages: 2.6-1.6 million years ago, 1.8-1.2 million years ago and 1.2-0.8 million years ago. The earliest stage presents ancient animals, such as *Sinomastodon*, *Hesperotherium*, *Dicoryphochoerus*, *Dorcabune* and *Cervavitus*. In the middle, the appearance of *Ailuropoda wulingshanensis*, *Cuon antiquus* and *Tapirus sinensis* marks a new stage. The final stage brings forth a typical Mid-Pleistocene lineup, such as: *Ailuropoda baconi*, *Stegodon*, orangutans, macaques, rhinoceros, *Sus xiaozhu* and *Sus peii*, the muntjac, *Cervus*, gaurs, *Megalovis* and (rarely) *Megantereon*.

Longgudong Cave possibly represents a transitional zone, between the Palearctic and Oriental realms, with more boreal animals like hedgehogs, hyenas, horses, pikas and *Leptobos*. In Lang Trang, Vietnam, *G. blacki* lived alongside *Macaca* spp., *Pongo*, tigers, *Presbytis*, *Neofelis*, *Arctonyx*, *Chodsigoa*, *Hystrix*, *Leopoldamys*, *Rattus*, *Elephas*, *Tapirus*, *Dicerorhinus*, *Sus*, *Muntiacus*, *Axis*, *Rusa*, *Capricornis* and *Crocodylus*.

*Gigantopithecus* likely went extinct ~300,000 years ago, likely due to the habitat (including forests) retreating south during the Middle Pleistocene, due to increasing seasonality and monsoon strength alongside cooling. Until the Late Pleistocene, savanna would stay as the dominant environment. Some speculate immigrating *Homo erectus* contributed towards the ape's extinction, as human activity dates back 800,000 years ago, but becomes prevalent until after *Gigantopithecus* disappears. It is unclear if competition or overhunting pressures were factors. *Homo erectus* was better suited towards the savannah.

## Cryptozoology

*Gigantopithecus* is often used as an identity for cryptids such as bigfoot, the yeti or other humanoid monsters, such as ones seen in folklore. Wladmir Tschernezky started this in 1960 when describing a 1951 photograph of alleged yeti tracks discovered by Michael Ward and Eric Shipton in a publication in Nature. Concluding the cryptid walked bipedally and looked like *Gigantopithecus*, the yeti received short scientific attention, with several publications in Nature and Science, inciting a following for bigfoot and the yeti, which has persisted today. Grover Krantz, the only scientist who keeps trying to prove their existence, continued pushing the bigfoot-Gigantopithecus connection from 1970-2002, when he passed. Among the names he coined were "G. canadensis", "Australopithecus canadensis" and "*Gigantanthropus canadensis*". Today, experts say he did not receive support from the mainstream scientific community or amateurs, saying he accepted obviously fake evidence with open arms. The names *G. canadensis*, *Gigantopithepodus* and *Anthropoidipes ameriborealis* have been used to describe cryptohominid tracks from North America that are giant and referred to be some cryptozoologists to be of *Gigantopithecus* (although the trackmakers are recent). Some suggest that Chinese cryptohominids (including the yeren) are relict *Gigantopithecus* or pongine that live in isolate breeding populations in remote areas. This seems unlikely, and the yeren specifically are likely a caricature for bearded Europeans and misidentified animals. After formal description, von Koenigswald reportedly received numerous letters asking if his taxon was the same as the yeti, to which he replies: "I do not think so".

## References

1. ↑ https://cryptidarchives.fandom.com/wiki/Bigfoot
2. ↑ https://en.wiktionary.org/wiki/Gigantopithecus
3. ↑ 3.0 3.1 3.2 https://www.researchgate.net/publication/316650973\_Giant\_Primate\_of\_Java\_A\_New\_Gigantopithecus\_Specimen\_from\_Semedo
4. ↑ https://paleobiodb.org/classic/displayCollResults?a=basicCollectionSearch&collection\_no=108001
5. ↑ https://paleobiodb.org/classic/displayCollResults?a=basicCollectionSearch&collection\_no=92781
6. ↑ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 https://en.wikipedia.org/wiki/Gigantopithecus
7. ↑ https://www.elibrary.ru/item.asp?doi=10.31857/S2686738922010140
8. ↑ https://onlinelibrary.wiley.com/doi/full/10.1002/ajpa.23150
9. ↑ https://link.springer.com/article/10.1134/S1028334X22060101
10. ↑ https://cryptidarchives.fandom.com/wiki/Bigfoot
11. ↑ https://cryptozoologicalreferencelibrary.files.wordpress.com/2019/10/woodley-2011.pdf
12. ↑ https://www.sasquatchcanada.com/uploads/9/4/5/1/945132/meldrum\_paper\_-\_ichnotaxonomy.pdf
13. ↑ https://cryptozoologicalreferencelibrary.files.wordpress.com/2021/03/smith-2021.pdf
14. ↑ https://unesdoc.unesco.org/ark:/48223/pf0000064099