If you were to go for a walk in the forests
of Southeast Asia during the Ice Age, you’d probably see a lot of awesome, and familiar,
creatures – like rhinos, tapirs, and hyenas. But an animal once wandered these woods that
was unlike anything you’ve ever seen. About 3 metres tall and weighing up to 500
kilograms, this beast was probably twice the size of a modern gorilla. Scientists call it Gigantopithecus, the greatest
great-ape that ever was. And for us fellow primates, there are some serious
lessons to be learned in how it lived, and why it disappeared. So the story of Gigantopithecus begins with the
some of the smallest of physical clues -- teeth. And they weren't found in the field, but in
a drug store. In 1935, paleontologist Ralph von Koenigswald
was rummaging through apothecary shops in Hong Kong. He was looking for so-called dragon teeth
-- the name given to fossil teeth from all sorts of animals that were used in traditional
Chinese medicine. And on one of these trips, von Koenigswald
found a molar unlike any he’d seen before. The tooth was like that of an ape, broad and
flat, but it was a much bigger one from any known species, living or extinct. Von Koenigswald eventually determined that
these teeth were of an enormous primate, and he named this new creature Gigantopithecus,
or “giant ape.” After this initial discovery, more teeth were
found in other medicinal shops, and eventually a few fossil jawbones were found in a Chinese
cave. But that was it. Since then, we’ve found more jaws and thousands
of teeth. But no other parts of the giant ape’s body
have ever been discovered. Even though we have so little of its anatomy
to study, we’ve managed to figure out a lot about Gigantopithecus just from those
teeth and jaws. For starters, it turns out there were three
species of this giant ape, the earliest of which dates back about 9 million years, to
the Miocene epoch. But the most recent, and by far the largest
of them, was Gigantopithecus blacki It lived from 2 million to 100 thousand years
ago during the Pleistocene epoch, in what’s now south China and Vietnam. Of course, the most obvious feature of Gigantopithecus
blacki’s teeth is their size. At 2 and a half centimeters wide, the ape’s
molars were more than twice the width of a human tooth. But an even closer look at these teeth has
revealed much more than just how big this animal was. For one thing, scientists have been able to
use them to figure out who its closest living relatives are. In 2008, a team of anthropologists studied
the thickness of the enamel on ten Gigantopithecus teeth, as well as the shape of the hard tissue
underneath it, called the dentin. They found that the structure and the composition
of the fossil teeth were most similar to those of the only great apes left in Asia – the
orangutans. Which is … kind of strange. Because orangutans are arboreal; they spend
most of their time high in the trees. But Gigantopithecus was way too big to do
that. So, scientists think it must’ve been a ground-dweller. Which raises a new set of questions. For one thing, what does a 500-kilogram primate
eat? Well, its teeth were flat and wide, but its
jaws were deep and strong – and all of these features are associated with feeding on tough,
fibrous plants. Microscopic plant fossils, called phytoliths,
have also been recovered from some teeth, showing that it fed on grasses -- including
possibly bamboo -- as well as seeds and fruit. But while these physical clues can tell us
a lot about the diet of this extinct ape, the chemical composition of its teeth can
also reveal to us where it lived. And possibly, why it disappeared. The trail of clues here begins with isotopes
of carbon. Different kinds of plants produce different
ratios of carbon isotopes during photosynthesis, depending on what kinds of environments they
live in. For example, plants that live in cool, humid
climates are typically what’re known as C3 plants, because their way of photosynthesizing
results in a 3-carbon acid that has its own unique combination of carbon isotopes. But plants that grow in hotter, drier climates
are usually C4, because they do photosynthesis in a slightly different way, and produce their
own byproducts with their own ratios of carbon. And this is all extremely useful for scientists,
because the chemical signatures in these plants are absorbed by the animals that eat them. So by studying the chemistry of Gigantopithecus
teeth, researchers can tell not only what kinds of food it ate, but also possibly what
its Ice Age habitat was like. And in 2011, paleontologsts from China studied
the tooth enamel of Gigantopithecus and found that it fed exclusively on C3 plants -- the
ones that tend to grow in cool, humid forests rather than warm, grassy plains. At the same time, though, fossils of other
mammals that lived alongside the ape have been studied too -- I’m talking about those
rhinos, tapirs, and hyenas I mentioned earlier. And it turns out, they ate some C3 plants,
but also C4 plants, which grow in drier, grassy areas. So this suggests that Gigantopithecus probably
lived in a mosaic habitat, kind of like a checkerboard of forests and grasslands. But unlike its fellow herbivores, Gigantopithecus
preferred to live only under the dense forest canopy and didn’t stray into the open -- much
like modern orangutans and mountain gorillas, who are also forest experts. And this specialist lifestyle seemed to work
very well, at least for a while. The fossil record shows that Gigantopithecus
blacki existed for nearly 2 million years in the forests of southeast Asia. But these primates lived during a time of
great change. The Pleistocene is sometimes called the Ice
Age, when glaciers were constantly ebbing and flowing across the land, holding moisture
when they froze and releasing it again when they thawed. This constant fluctuation meant that Pleistocene
habitats were in an ongoing state of flux. Things could be warm and humid for 20,000
or 100,000 years or so, which would allow forests to grow. But then it would freeze again and draw all
the moisture back up to higher latitudes, and grasslands would spread. Somehow, Gigantopithecus managed to survive
the first few of these glacial periods, but 100 thousand years ago, in the Middle Pleistocene,
something changed. Another cold snap occurred that was simply
too severe for the apes to survive. As the ice expanded, so did the grasslands,
shrinking the forests of Southeast Asia. Without the habitat it needed to survive,
populations of Gigantopithecus shrank dramatically. And by 100,000 years ago, the last of Gigantopithecus
had vanished. So Gigantopithecus managed to thrive for as
long as it did because it was a specialist -- it found the right combination of food
and habitat to suit its probably massive needs. But in the end, its specialized habits left
it vulnerable in an ever-changing world. And in this way, its predicament is similar
to that of many modern animals, including its closest living relatives, the orangutans. Orangs are forest specialists, too, only found
in the dense jungles of Borneo and Sumatra. But for decades their unique forest homes
have been reduced by things like logging and wildfires. With much of their habitat gone, all three
species of orangutan are now considered critically endangered. Still, some researchers hold out hope that
we can help these distant cousins of Gigantopithecus -- and of us! -- by continuing to learn the
story of the greatest ape that ever lived. Now, what do you want to know about the story
of life on Earth? Let us know in the comments. And don’t forget to go to youtube.com/eons
and subscribe! But don’t stop here! Do yourself a favor and check out some of
our sister channels from PBS Digital Studios!
Was pleasantly surprised to see Kallie Moore of the University of Montana Paleontology Center presenting this. Definitely will be incorporating this video into introductory courses on human evolution and/or primate paleontology when discussing Gigantopithecus and East Asia.
I'm so glad I found this channel.
He's suspended for one week after a late hit on Tre'Davious White. He'll be back vs the Steelers, tho