Rise and fall of the greatest ape of all time

At three meters tall, Gigantopithecus blacki was a giant ape that wandered for a long time through the jungles of Asiabefore disappearing from the face of the Land more than 200,000 years ago.

And everything indicates that it was due to their inability to adapt to changes in their environment, according to a study published this Wednesday.

The extinction of the largest primate of all time, weighing 200 to 300 kilos, was one of the great enigmas of paleontology since the first fossils of the beast appeared in the 1930s.

A German paleontologist had found in those years what was presented to him as a “Dragon tooth” in a pharmacy in Hong Kong.

“It was three or four times larger than that of any great ape. This intrigued him and so the investigations began.says Renaud Joannes-Boyau, professor at Southern Cross University in Australia, one of the main authors of the study published in Nature.

Gigantopithecus blacki barely left behind some jaws and teeth. Hundreds of these fossils were found in caves in Guangxi province, southern China.

Despite ten years of excavations, scientists were unable to determine when the species became extinct and therefore why, explained Professor Yingqi Zhang of the Institute of Paleontology of the Chinese Academy of Sciences, lead co-author of the study.

The disappearing window

Instead of investigating site by site, a team of Chinese, Australian and American scientists worked on a set of 22 caves, some of which had never been excavated before. There they found fossilized teeth, between 2 million and 250,000 years old.

They combined six different dating methods, including luminescence sediment analysis, which allows us to know when these deposits were last exposed to daylight.

They also used dating of pollen remains, which is a valuable indicator of vegetation evolution.

All this in order to “have a well-defined chronology of the environment of each site, even those where Gigantopithecus blacki stopped appearing,” explains Professor Joannès-Boyau, an expert in geochemistry.

Their results allowed us to determine a “extinction window” of the species: between 295,000 and 215,000 years.

This corresponds to a broad period of glacial cycles called the Pleistocene, when the planet experienced global cooling.

Too specialized

As a result, in the lush rainforests where the colossus thrived, “the appearance of seasons transformed the vegetation and caused periods of fruit scarcity,” explains researcher Kira Westaway, from Macquarie University in Australia, main co-author of the study.

The Gigantopithecus blacki moved alone on the ground, and little by little it saw its food search area decrease and began to feed on bark and small branches.

“They made a huge mistake by specializing in these emergency foods, very fibrous and less nutritious”Yingqi Zhang detailed in an interview with AFP in Beijing.

Its too large size slowed down the agility needed to find more varied resources. This disadvantage only got worse as “surprisingly, its size increased” over time, Kira Westaway notes.

The animal began to suffer “long-term chronic stress”, which is reflected in the teeth. The population gradually declined and the species eventually became extinct.

On the contrary, their contemporaries, the orangutans of the Pongo weidenreichi species, close to Gigantopithecus, resisted: they were smaller and more agile, capable of moving through the treetops to find a more varied diet (leaves, nuts, insects, small mammals, etc.).

That saving versatility grew stronger as his size decreased over time. Gigantopithecus was not the only animal from the Pleistocene megafauna that disappeared.

According to Kira Westaway, “exploring these unresolved extinctions allows us to understand the mechanisms of resilience in large animals, both in the past and in the future, in the face of the threat of a sixth mass extinction” of species.