According to scientists’ best estimates, the giant ape known as Gigantopithecus blacki stood as tall as 9 feet and weighed around 1,000 pounds. It lived in what is now southern China and mainland Southeast Asia some 100,000 years ago, when that land was covered in semi-tropical forest. But after a massive ice age during the Pleistocene epoch caused much of Earth’s forests to change to grassland, shrinking the supply of the fruit that was its primary source of food, Gigantopithecus failed to adapt for some reason. According to a new study, the giant ape’s refusal to add grass, roots and leaves to its diet—as other ape and early human species did—led to its extinction.
When European scientists first encountered the fossilized teeth of Gigantopithecus in the 1930s, Chinese pharmacies were marketing the enormous dental specimens as “dragon’s teeth.” First identified as a species in 1935, Gigantopithecus immediately earned comparisons to King Kong, the fictional giant ape who had captivated movie audiences in the blockbuster movie two years earlier.
In the new study, published in a recent issue of the journal Quaternary International, a team of German researchers led by Herve Bocherens of Tübingen University examined all the an fossils known to survive, including hundreds of teeth as well as four partial lower jawbones. The remains are not enough for scientists to say whether the animal was bipedal or walked on all fours, or to determine anything more concrete about its body proportions. Though they know its closest modern cousin is the orangutan, it is also unknown whether Gigantopithecus’ coat was golden-red like that animal or black, like the gorilla.
By analyzing the carbon isotopes in its tooth enamel, the researchers in the new study found that Gigantopithecus was a strict vegetarian and probably didn’t like eating bamboo. (This contradicts the findings of a Chinese team in 2011 that Gigantopithecus subsisted on a diet of bamboo, and that a massive dying-out of those plants spelled its end.) The German researchers also found that the giant ape didn’t stray from its forest habitat, though it was probably too heavy to climb trees or swing from branches.
To survive, Gigantopithecus consumed massive quantities of fruit. This narrow diet caused problems after the ice age caused the climate to change, converting a growing number of Earth’s forest into savannah or grassland. While other apes and early humans with similar dental capacities living at the time added grass, roots and leaves to their diet, Gigantopithecus failed to do so for some reason that remains unclear to the scientists. As the study’s authors note: “Gigantopithecus probably did not have the same ecological flexibility and possibly lacked the physiological ability to resist stress and food shortage.”
Too big to survive when their food supply diminished, Gigantopithecus instead went extinct in the wake of the climate change. Beyond that, however, scientists will probably never know whether its picky eating habits can be explained by some genetic cause, or whether the giant ape could have adapted but didn’t for some other reason.