The largest primate in our family tree went extinct hundreds of thousands of years ago, and its existence has been known to humankind for less than a century. Now, a team of researchers has reviewed the ancient records and devised a more specific extinction window for our huge fallen relative, Gigantopithecus blacki, and pointed out a few possible causes for its demise.
The ape went extinct between 295,000 and 215,000 years ago, according to the new study. As the climate of southeast Asia changed, G. blacki could not change its eating habits or habitat. Its geographic footprint diminished, and before long, only fossilized teeth remained. The new research is published today in Nature.
“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?” said lead author Yingqi Zhang, a paleontologist at the Institute for Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences, in a statement. “The unresolved cause of its disappearance has become the Holy Grail in this discipline.”
The search for the largest primate to ever exist began in 1935, when a German paleontologist happened upon a “dragon’s tooth” in a Hong Kong apothecary. It was a molar—not of a dragon, obviously, but an extinct ape, one that is estimated to have stood nearly 10 feet (3 meters) tall and weighed up to 661 pounds (300 kilograms).
Scant evidence of G. blacki remains, tucked away in caves in southeast Asia. The ape’s fossil record is comprised of four mandibles and 2,000 teeth, the recent team reports. But their study expands the fossil record, drawing on newly discovered remains excavated from caves between 2017 and 2020. Prior to that, Zhang had found six caves containing G. blacki remains over the course of a decade. Twenty-two caves were sampled for the recent paper, and six dating techniques were used to corroborate the timeline of the ape’s extinction.
Besides the fossil remains, the team looked at ancient pollens, sediments, and isotopes locked away in the cave floors, to understand the changing climate G. blacki was facing. Other apes faced it, too, including one of the giant ape’s closest relatives, Pongo weidenreichi, an ancient species of orangutan.
The researchers determined that, as the climate changed, G. blacki didn’t adapt like its relatives in the region. As its food sources became unavailable due to the changing climate—the forest and grass ecosystem gave way to an open forest environment—G. Blacki resorted to less nutritious foods.
“G. blacki was the ultimate specialist, compared to the more agile adapters like orangutans, and this ultimately led to its demise,” Zhang said.
Though P. weidenreichi also went extinct, it did so around 60,000 years ago—much more recently than the giant apes with which it shared southern Asia. And of course, three orangutan species remain extant, although all are critically endangered.
“Understanding the causes of primate extinction is crucial with the threat of a sixth mass extinction event looming over the planet,” said co-lead author Kira Westaway, a geochronologist at Macquarie University, in an email to Gizmodo. “Going back to past unresolved extinctions and determining the causes helps us understand species responses to environmental stresses. This has massive implications for our living primates such as modern orangutans and mountain gorillas.”
The climate is changing, and great apes are losing habitat due to human activities—farming, mining, and logging amongst them, according to the World Wildlife Fund. The orangutan is the only great ape left in Asia, and it is being pushed to extinction by palm oil producers.
It’s easy to rue to loss of G. blacki, an animal of wondrous scale, but it will be even more painful to lose species we’re familiar with—which is why a global response to climate change is so crucial.
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