3 Theories Why The Largest Ape Of All Time Went Extinct

Gorillas are pretty big, right? The big silverback males are jacked enough to shame a human bodybuilder into absolute subservience. They're not too tall — just about 5 feet. But they weigh about 430 pounds and can lift almost 1,800 pounds. By comparison, absolute freak-of-nature and one of the strongest humans alive, 6-foot-9-inch Hafthor "The Mountain" Björnsson, once deadlifted 1,104 pounds. Just to help the reader visualize: Shaq is 7-foot-1. So what do we say to a hominid that's about 10 feet tall? We say: "By all means, sir, you eat first."

Yes, Gigantopithecus — as the very obvious name says — was gigantic. This biggest of apes roved the planet during the Pleistocene Era (from 2.6 million years ago to 11,700 B.C.E.), and went extinct somewhere between 295,000 and 215,000 years ago. They were forest dwellers concentrated in modern-day South-Central China, at least according to fossil records from 22 caves in the region. Other fossils were found in Vietnam and Thailand, but they might be from a similar, related species.  

So if Gigantopithecus was so big and presumably powerful, why did it die out and help make space for we tiny Homo Sapiens, i.e., "wise humans" (a generous assessment). To answer, we can look at Gigantopithecus's closest relative, the orangutan, with whom it shares a common ancestor about 10 to 12 million years ago. Orangutans are pretty docile, chill, and eat mostly a diet of fruit supplemented by insects. Sumatran orangutans rarely eat meat, but Borean orangutans never touch the stuff. Gigantopithecus, though, was completely herbivorous. This, plus a bunch of related reasons, provide answers about why it went extinct.

You know that one strategy when making kids eat things they don't like? We're talking about the, "Well, I guess you're not eating tonight, are you mister?" strategy. While the effectiveness of this strategy is definitely limited and will likely make a kid freak out more than rhetoric them into submission, the logic holds in many respects. If you don't eat X, then you must eat Y. And if there isn't enough of X to eat and you refuse to eat Y, then you don't have enough to eat. And if you continue not having enough to eat, you die. See, kids? Eat your vegetables.

So what if an entire species abided by this obstinate way of being? Not that it would have been a wholly conscious choice for Gigantopithecus to huff a bit, cross its very long arms, and refuse to eat anything but bananas. But conscious or not, this is one of the prevailing ideas regarding why Gigantopithecus went extinct. They loved their fruit, didn't or couldn't eat anything else, and when they couldn't get enough fruit, they all died.

We know what Gigantopithecus ate based on the fossils found in the 22 caves we mentioned. Their molars were enormous and dubbed "dragon teeth" when they were first found. Per a study published in Nature, those teeth and their enamel reveal a "specialized herbivore with adaptations for the consumption of abrasive food, heavy mastication of fibrous food, and a fruit-rich diet." As to why Gigantopithecus didn't or couldn't eat enough fruit: That's a different story.

Gigantopithecus was shaped by its environment, like all other species. The oldest Gigantopithecus teeth date from a long span of 2 million years to 300,000 years ago, and we already mentioned that the species died off from 295,000 to 215,000 years ago. But no matter how we assess the species' lifespan: That's a lot of time for Gigantopithecus to live in one climate and have one, very specific herbivorous diet. It's also a long enough time for the environment to change, perhaps too quickly for Gigantopithecus to keep up.

On that note, lots of evidence points to changes in Gigantopithecus' habitat that led to "dry periods when fruits were difficult to find," per Kira Westaway of Macquarie University in Australia in The New York Times. A dense, wetter forest slowly gave way to scattered forests and grasslands. Over this period of time, Gigantopithecus' teeth showed "signs of chronic stress" as the species turned from fruits, nuts, seeds, etc., to tree bark and even twigs. Water in the area also dried up. At the same time, the ancestors of modern-day orangutans expanded their food sources to include leaves from trees, insects, and small animals. And so we come to a problem we already mentioned: Gigantopithecus didn't or couldn't change its diet.

Little by little, fossil records indicate that Gigantopithecus' presence shrunk from China's Guangxi, Guizhou, Hainan, and Hubei Provinces to only its Guangxi Province. It stands to reason that Gigantopithecus found this environment the most hospitable and survived there the longest.

We mentioned that Gigantopithecus was big. It was twice as tall as a silverback gorilla (10 feet vs. 5 feet) and about 1.5 times as heavy at the largest (660 pounds vs. 430 pounds). Of course, there was certainly variation between individuals and between males and females, and Gigantopithecus wasn't as stocky as modern-day gorillas. Still, it isn't hard to imagine that Gigantopithecus had to spend a lot of time prowling for food, especially if it preferred things like fruit. Modern-day orangutans, their closest cousin, spend up to 90% of the day looking for food when fruit is in short supply, and they have a more liberal diet than Gigantopithecus.

But even though The New York Times says that Gigantopithecus was "not too big to fail," size played a role, especially as the ape's environment changed and its food sources became scarce. Even aside from running out of food, Gigantopithecus was too big to get around easily or forage far from home. Proto-orangutans could swing through trees, were more nimble overall, and could travel further from their preferred areas. Gigantopithecus was ground-bound. And, it was also too slow to chase down prey.  

In the end, each theory about why Gigantopithecus went extinct holds water, interconnects with the other theories, and is likely in some way true. The biggest ape to roam the globe had a restrictive diet, lost the fight to environmental change, and was too big to do anything about it. There's a lesson somewhere in there for us humans, no matter how tiny we are.