The world’s largest ape vanished from Earth more than 100,000 years earlier than once thought, pushed to extinction as the environment around it shifted, researchers report January 10 in Nature.
The new extinction date comes from new analyses of fossils of Gigantopithecus blacki, as well as on the sediments of about a dozen caves in southern China where the ape once dwelled. Instead of dying out around 100,000 years ago, the ape was driven to extinction between 295,000 and 215,000 years ago, the team found.
The fate of G. blacki, twice the size of the largest modern apes and resembling a super-sized version of its close cousin, the orangutan, has long been a mystery (SN: 11/13/19; SN: 6/24/44). For about 2 million years, G. blacki inhabited a mosaic landscape of forests and grasses in what’s now southern China. It left behind only scattered remnants: thousands of teeth and four jawbones, unearthed in cave sediments in the region.
To establish a chronology for the ape’s extinction, paleoanthropologist Yingqi Zhang of the Chinese Academy of Sciences in Beijing and colleagues assembled an array of different dating techniques to determine the ape’s habits, diet and environment. In the teeth, they looked for data on the ape’s diet, measuring isotopes of carbon and oxygen as well as examining the teeth for tiny evidence of wear and tear — which can reveal not only diet, but also give hints of repeated behaviors and stress. The team also analyzed the cave sediments bearing the fossils, hunting for fossil pollen and conducting luminescence dating on radioactive elements within the sediments.
The team’s reconstruction revealed that around 700,000 to 600,000 years ago, southern China shifted from its forested landscape to a more seasonally-driven environment. Some apes, including the orangutans, were able to adapt to these changes. But G. blacki was unable to change rapidly enough, and its numbers slowly dwindled before going extinct, the team suggests.
The assembled evidence tells a convincing story that “the demise of Gigantopithecus coincided in southern China with a decrease of forest cover and expansion of savanna-like environments,” says Hervé Bocherens, a biogeologist at the University of Tuebingen in Germany. Still, he says, documenting the extinction of this species from the fossil record is tricky — and it’s impossible to rule out the possibility that pockets of G. blacki may have lingered in still-undiscovered caves for longer.
Understanding the fate of this ape, the researchers say, helps reveal how modern environmental pressures might push orangutans, now on the brink of extinction as their habitat shrinks, over the edge (SN: 1/25/06).