The extinction of the largest known primate, a giant ape from China, resulted from its struggle to adapt to environmental changes, as per a paper published in Nature. These findings fill a key gap in our understanding of why this species failed to survive where other, similar primates persisted.
Gigantopithecus blacki was a species of great ape that was found in China between 2 million and 330 thousand years ago, after which the species became extinct. With an estimated height of 3 m and weight of 200–300 kg, it is thought to be the largest primate to ever exist on Earth. The distribution of the most recent fossils suggests that the geographical range of G. blacki markedly reduced prior to their extinction. An exact timeline and reason for this decline has yet to be established.
The researchers collected and dated fossil samples from 22 caves in southern China. Analyses of the teeth of G. blacki and Pongo weidenreichi (their closest primate relative) were used to determine changes in diet or behaviour of the species within the extinction window, in conjunction with pollen and stable isotope analysis to reconstruct the environment.
Pollen analysis indicates that 2.3 million years ago, the environment was made up of dense forests with heavy cover — conditions to which G. blacki was well-suited. Prior to and during the extinction window (295–215,000 years ago), changes in forest plant communities led to a transition in the environment with open forests dominating the landscape. The transition to open forest is reflected in the dental analyses, which suggest that the diet of G. blacki became less diverse and with less regular water consumption; accompanied by indications of increased chronic stress among G. blacki over this period. This is in contrast to P. weidenreichi, which shows much less stress and better adaption of its dietary preferences to changing conditions over this same period. The fossil numbers support these hypotheses, showing a decline in the number and geographical spread of G. blacki fossils in the record relative to P. weidenreichi by 300 thousand years ago.
The authors present a precise timeline for the demise of G. blacki that suggests it struggled to adapt to a changing environment compared to its primate peers.
