Mysteries solved on the largest ever primate: 3m tall ape

The extinct giant apes of southern China, which were up to 3 metres tall and weighed as much as 250 kilograms, have long puzzled palaeontologists.

We know these massive creatures, called Gigantopithcus blacki, existed from 2,000 teeth and 4 jawbones they left behind, but when and how they went extinct was a mystery.

Until now. The results of an extensive dating project by Chinese, Australian and US researchers have today been published in Nature and it’s now believed they were victims of environmental change.

“The story of G. blacki is an enigma in palaeontology – how could such a mighty creature go extinct at a time when other primates were adapting and surviving?” says co-lead author Professor Yingqi Zhang, from the Institute of Vertebrate Palaeontology and Palaeoanthropology at the Chinese Academy of Sciences (IVPP).

“The unresolved cause of its disappearance has become the Holy Grail in this discipline.”

Orangutans (Pongo weidenreichi), which are quite similar to G. blacki, are among the primates that have gone on to thrive.

“The IVPP has been excavating for G. blacki evidence in this region for over 10 years but without solid dating and a consistent environmental analysis, the cause of its extinction had eluded us.”

The researchers used 6 different dating techniques on evidence from 22 caves – 11 that contained evidence of G. blacki and 11 that didn’t – all in the southern Chinese province of Guangxi.

This gave them 157 different ages for the fossil samples.

Combined with environmental analysis on things like pollen, cave sediments, and isotopes in teeth, the researchers were able to build a more thorough picture of G. blacki’s existence and extinction.

They found that 2.3 million years ago, the landscape was “a mosaic of forests and grasses, providing ideal conditions for thriving G. blacki populations”, according to their paper.

But the ape went extinct earlier than previously thought  ̶  between 295,000 and 215,000 years ago  ̶  at the same time the environment was becoming more variable.

The researchers believe that the ape was unable to adapt to the changing landscape, leading to a decline in its population.

“G. blacki was the ultimate specialist, compared to the more agile adapters like orangutans, and this ultimately led to its demise,” says Zhang.

“With the threat of a sixth mass extinction event looming over us, there is an urgent need to understand why species go extinct,” says co-lead author Associate Professor Kira Westaway, a geochronologist at Sydney’s Macquarie University.

“Exploring the reasons for past unresolved extinctions gives us a good starting point to understand primate resilience and the fate of other large animals, in the past and future.”