Deep inside a limestone cave in southern China, paleontologists have uncovered an assemblage of thirteen fossilized teeth belonging to Gigantopithecus blacki, the largest primate species ever known to have lived. The discovery fills a gap in the fossil record and offers new clues about how the species responded to a dramatic climatic change 1.2 to 0.7 million years ago.
An artist’s impression of a group of Gigantopithecus blacki within a forest in southern China. Image credit: Garcia / Joannes-Boyau, Southern Cross University.
Gigantopithecus blacki is an extinct great ape that once inhabited dense forests of Southeast Asia.
As its name suggests, this primate was larger than modern gorillas, standing up to 3 m (10 feet) tall and weighing as much as 540 kg.
The species survived from about 2.3 million years ago until its extinction roughly 295,000 to 215,000 years ago.
Gigantopithecus blacki was first described by the German-Dutch anthropologist Gustav von Koenigswald in 1935, based an isolated tooth he found in a Hong Kong drugstore.
The fossil record of the species consists of thousands of teeth and a handful of jawbones.
“Gigantopithecus blacki is hypothesized to have been the largest primate species,” said Dr. Yanyan Yao, a paleontologist at Shandong University, Nanning Normal University and the Anthropology Museum of Guangxi, and colleagues from China.
“Its fossil record is predominantly concentrated in the Early Pleistocene, followed by the Middle Pleistocene, while materials from the Early-Middle Pleistocene transition (1.2 to 0.7 million years ago) remain relatively scarce.”
Yanli Cave 1 in Chongzuo, Guangxi province, China. Image credit: Yao et al., doi: 10.16359/j.1000-3193/AAS.2026.0010.
The paleontologists found thirteen teeth of Gigantopithecus blacki — canines, premolars and molars from both the upper and lower jaws — at Yanli Cave 1 in Chongzuo, China’s Guangxi province.
The fossils date precisely to the Early-Middle Pleistocene transition (EMPT), a period when Earth’s climate became cooler, drier and more strongly influenced by glacial cycles.
The age estimate is based not on direct dating of the teeth but on the accompanying animal fossils.
The researchers identified specimens belonging to 30 species spread across 6 orders, including orangutan relatives, tigers, clouded leopards, tapirs, Javan rhinoceroses, stegodons and Asian elephants.
Two species within that assemblage were particularly telling for dating purposes: Ailuropoda wulingshanensis, a species of giant panda characteristic of the late Early Pleistocene, alongside Ailuropoda melanoleuca baconi, a subspecies of panda typical of the Middle Pleistocene.
The co-occurrence of both species is a strong signal that the deposit formed precisely during the transition between those two epochs.
“The faunal assemblage indicates a biostratigraphic age of EMPT,” the researchers said.
The Gigantopithecus blacki teeth from Yanli Cave 1 also appear to capture an evolutionary shift in progress.
Some specimens retained the relatively small tooth sizes typically seen in earlier populations, while others approached the larger dimensions common among later populations — a trend presumably linked to dietary adaptation.
“Comparative analysis of tooth dimensions with Gigantopithecus fossils from other localities reveals that some specimens from Yanli Cave 1 retain the relatively small-sized characteristic generally found in the early Early Pleistocene populations,” the scientists said.
“However, other specimens approach the large dental size commonly found in the late Early Pleistocene populations and larger size ranges documented in the Middle Pleistocene populations.”
“These findings are consistent with the biochronological assessment.”
“Following the discoveries at Queque Cave and Zhanwang Cave (both located at Chongzuo, Guangxi), Yanli Cave 1 represents as a third potential EMPT Gigantopithecus locality, likely offering crucial evidence for understanding dental evolutionary patterns and adaptive strategies in response to EMPT climatic shifts.”
The findings were published in the journal Acta Anthropologica Sinica.
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Yanyan Yao et al. 2026. Gigantopithecus blacki discovered in the Early-Middle Pleistocene transition phase in Yanli Cave 1, Chongzuo, Guangxi. Acta Anthropologica Sinica 45 (02): 199-209; doi: 10.16359/j.1000-3193/AAS.2026.0010
