''Gigantopithecus'' fossil sites range across Guangxi, Guizhou, Hainan and Hubei Provinces, but those post-dating about 400,000 years ago are only known from Guangxi. Its youngest definitive remains in China are roughly 295,000 to 215,000 years old,.<ref name="NAT-20240110"/> butTwo therepossible isteeth a(PIN possible5792/439 occurrenceand inPIN 5792/490) have been reported from the [[Late Pleistocene]] deposit in Vietnam.,<ref>{{Cite journal |last1=Lopatin |first1=A. V. |last2=Maschenko |first2=E. N. |last3=Dac |first3=Le Xuan |year=2022 |title=''Gigantopithecus blacki'' (Primates, Ponginae) from the Lang Trang Cave (Northern Vietnam): The Latest ''Gigantopithecus'' in the Late Pleistocene? |url=https://link.springer.com/10.1134/S0012496622010069 |journal=Doklady Biological Sciences |language=en |volume=502 |issue=1 |pages=6–10 |doi=10.1134/S0012496622010069 |pmid=35298746 |s2cid=254413457 |issn=0012-4966|url-access=subscription }}</ref> but this record has been subsequently suggested to instead represent a [[Chinese orangutan]] (''Pongo weidenreichi'').<ref>{{cite journal|author=Yingqi, Z.|title=Review and perspective of the ninety years in quest of ''Gigantopithecus blacki''|journal=Acta Anthropologica Sinica|volume=43|issue=6|pages=1006–1026|doi=10.16359/j.1000-3193/AAS.2024.0094|url=https://www.anthropol.ac.cn/EN/abstract/abstract2433.shtml}}</ref> The formerextinction of ''Gigantopithecus'' 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.<ref name="SunEtAl2019">{{cite journal |last1=Sun |first1=Fajun |last2=Wang |first2=Yang |last3=Wang |first3=Yuan |last4=Jin |first4=Chang-zhu |last5=Deng |first5=Tao |last6=Wolff |first6=Burt |date=15 June 2019 |title=Paleoecology of Pleistocene mammals and paleoclimatic change in South China: Evidence from stable carbon and oxygen isotopes |url=https://www.sciencedirect.com/science/article/abs/pii/S0031018218308381 |journal=[[Palaeogeography, Palaeoclimatology, Palaeoecology]] |volume=524 |pages=1–12 |doi=10.1016/j.palaeo.2019.03.021 |bibcode=2019PPP...524....1S |s2cid=134558136 |archive-date=14 November 2022 |archive-url=https://web.archive.org/web/20221114220312/https://www.sciencedirect.com/science/article/abs/pii/S0031018218308381 |url-status=live |url-access=subscription }}</ref><ref name=Shao2017>{{cite journal|first1=q.|last1=Shao|first2=Y.|last2=Wang|display-authors=et al.|year=2017|title=U-series and ESR/U-series dating of the ''Stegodon''–''Ailuropoda'' fauna at Black Cave, Guangxi, southern China with implications for the timing of the extinction of ''Gigantopithecus blacki''|journal=Quaternary International|volume=434|pages=65–74|doi=10.1016/j.quaint.2015.12.016|bibcode=2017QuInt.434...65S}}</ref> 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.<ref name="NAT-20240110"/> Similarly, ''Gigantopithecus'' seems to only have been consuming C<sub>3</sub> forest plants, instead of the C<sub>4</sub> savannah plants which were becoming more common during this time.<ref>{{Cite journal |date=2013-02-12 |df=dmy-all |title=New fossil evidence and diet analysis of ''Gigantopithecus blacki'' and its distribution and extinction in South China |journal=Quaternary International |language=en |volume=286 |pages=69–74 |doi=10.1016/j.quaint.2011.12.016 |issn=1040-6182 | last1 = Zhao | first1 = L.X. | last2 = Zhang | first2 = L.Z.|bibcode=2013QuInt.286...69Z }}</ref> Savannas remained the dominant habitat of Southeast Asia until the Late Pleistocene.<ref name="SunEtAl2019"/><ref name=Louys2020>{{cite journal|last1=Louys|last2=Roberts|first1=J.|first2=P.|year=2020|title=Environmental Drivers of Megafauna and Hominin Extinction in South East Asia|journal=Nature|volume=586|issue=7829|pages=402–406|doi=10.1038/s41586-020-2810-y|pmid=33029012|bibcode=2020Natur.586..402L|hdl=10072/402368|s2cid=222217295|hdl-access=free}}</ref>
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.<ref name="Ciochon2009">{{cite journal |last=Ciochon |first=Russell L. |author-link=Russell Ciochon |date=17 June 2009 |title=The mystery ape of Pleistocene Asia |journal=Nature |volume=459 |issue=7249 |pages=910–911 |bibcode=2009Natur.459..910C |doi=10.1038/459910a |pmid=19536242 |doi-access=free}}</ref> Zhang et al. in 2024 suggested that there is no evidence of any archaic hominin involvement in the early extinctions of the Pleistocene of southern China.<ref name="NAT-20240110"/>
