A study published in the journal Nature has revealed how the extinct ape, known as Gigantopithecus blacki, disappeared due to its inability to adapt to a changing environment.
G. blacki was found in what is now southern China around two million years ago until the species went extinct before the arrival of humans in the region. The ape grew to an estimated height of about 10 feet and may have weighed roughly 440 to 600 pounds.
These creatures, which are very distant ancestors of humans, belong to the group of great apes known as Ponginae, whose only living members are the orangutans. Researchers speculate that G. blacki would likely have resembled an orangutan—albeit significantly larger—although this will only be confirmed once more fossils are found.
The first evidence of Gigantopithecus came in 1935 when anthropologist Ralph von Koenigswald came across an unusual specimen in a traditional Chinese drugstore in Hong Kong. Labeled as “dragon teeth,” von Koenigswald discovered the molars belonged to an unidentified species of extinct ape he called Gigantopithecus.
Even today, just 2,000 fossilized teeth and four jawbones are the only evidence of their existence, meaning we have little idea of what they truly looked like.
G. blacki is sometimes called the “real-life King Kong” owing to its gargantuan size, although it is more closely related to orangutans from the Ponginae family. If you’ve seen the 2016 remake of The Jungle Book, the figure of King Louie is said to have been based on G. blacki.
“The Jungle Book basically made him a large orangutan. We don’t know how much G. blacki would have looked like an orangutan but it was definitely a Pongine, so in the right family. As for the orange fur – we really don’t know,” Associate Professor Kira Westaway, a researcher at Macquarie University whose new study investigated the extinction of G. blacki, told IFLScience.
“The IVPP has been excavating for G. blacki evidence in this region for over 10 years but without solid dating and a consistent environmental analysis, the cause of its extinction had eluded us.”
Zhang knew that a significant component of this mystery was the timing, so he decided to involve Westaway, a geochronologist.
“I am able to date the burial sediments that surround the G. blacki fossils. We have been working together since 2015 trying to solve the mystery of its demise,” Westaway told Newsweek.
In the latest study, the scientists and their colleagues applied a multidisciplinary analysis to 22 caves in Guangxi Province, southern China. First, the team used dating techniques to establish a “window of extinction” during which the great ape disappeared between around 295,000 and 215,000 years ago.
“We have a much more robust timeline for their life and when they went extinct—rather than being based on evidence from one or two caves, we have sampled 22 caves over a wide area and employed six dating techniques to make sure that the timeline is accurate,” Westaway said.
This window provided the researchers with a reliable time period to investigate the contemporary environmental conditions and how G. blacki was behaving and responding to its changing world.
The researchers reconstructed detailed environmental conditions during the extinction window using an analysis of pollen, fossils, sediments and stable isotopes (atoms of the same element that have the same number of protons but a different number of neutrons).
This showed that from around 2.3 million years ago, the environment consisted of a mosaic of dense, rich forests and grasses. This environment, characterized by diverse food and plentiful water sources, provided ideal conditions for G. blacki to thrive alongside other primates.
But by around 700,000-600,000 years ago, the researchers observed a shift towards a more seasonal climate, which sparked changes in plant communities and increased open forest environments. This environment was characterized by less diversity in food sources.
The researchers also analyzed the teeth of G. blacki and Pongo weidenreichi—their closest primate relative—to determine changes in the diet and behavior of the species in this period. This revealed that G. blacki, the ultimate specialist, was not good at adapting to the changing conditions, displaying signs of chronic stress. Meanwhile, the fossil record indicates a decline in the number and geographical spread of G. blacki, with the evidence suggesting that the population was struggling around 300,000 years ago.
On the other hand, P. weidenreichi (the Chinese orangutan) appears to have fared better in the same period, adapting more effectively to the changing environment (although this species would also eventually go extinct around 66-57,000 years ago).
“The more seasonal climate created dry periods when fruits were difficult to find,” Westaway said. “G. blacki relied on a less nutritious fallback food, such as bark and twigs. Whereas P. weidenreichi was more flexible in its fallback food, eating shoots, leaves, flowers, nuts, seeds—even insects and small mammals.”
“G. blacki‘s range for foraging was restricted by its size. But P. weidenreichi was more mobile traveling in the canopy for longer distances, allowing a greater range for foraging. G. blacki stayed in the forest whereas P. weidenreichi was able to move into more open forest environments.”
The latest findings, thus, shed new light on the demise of the largest primate ever to have roamed the Earth. Ultimately, the struggle of G. blacki to adapt to its changing environment led to the extinction of the great ape, according to the study.
“Understanding the causes of primate extinction is crucial with the threat of a sixth mass extinction event looming over the planet,” Westaway said. “Going back to past unresolved extinctions and determining the causes helps us understand why some species are more vulnerable and why others are more resilient.”
