Largest monkey in history disappeared due to end of forests – 01/10/2024 – Science

The end of the largest primate of all time, a relative of orangutans that may have reached 3 meters in height, was probably triggered by the progressive loss of the forests where it fed until some 300,000 years ago.

The conclusion comes from a study that mapped the entire trajectory of the species Gigantopithecus blackiwho lived in southern China and whose fossils begin to appear in geological layers from the beginning of the Pleistocene (the Ice Age), 2.2 million years old.

The species is still enigmatic, in part because the fossils found to date only correspond to the monkey’s oral anatomy: four jaws and around 2,000 isolated teeth. The size of the molars and jaw, however, are enough to estimate that the animal would have reached up to 300 kg in weight – 50% more than the largest male gorillas today.

The comparison to today’s gorillas also makes sense when considering that the ape appears to have been strictly herbivorous. The teeth of the Gigantopithecus it has characteristics that indicate an adaptation to consume fibrous plant matter, abundant fruits and abrasive plants (capable of wearing down teeth).

In the new research on the super primate, which has just been published in the specialized journal Nature, scientists from Chinese, Australian and South African institutions focused their efforts on two fronts. On the one hand, they carried out detailed analyzes of 22 Chinese caves with and without fossils of the species, to try to date the primate’s presence accurately over time, and also to reconstruct changes in its environment over time.

On the other hand, the chemical composition of the animals’ teeth was examined to try to understand the changes in their diet and lifestyle over time. It was also possible to compare these dental characteristics of the Gigantopithecus with those of a much smaller contemporary monkey. This is the Pongo weidenreichian ancient orangutan.

“O P. weidenreichi survived the extinction of Gigantopithecusand there are fossils of it in this region up to 57 thousand years ago, although we are not sure when they disappeared from China,” he told Sheet researcher Kira Westaway, from the School of Natural Sciences at Macquarie University, in Australia, and one of the coordinators of the study in Nature. Today, orangutans are only found on the islands of Sumatra and Borneo, but their continued presence on mainland Asia until relatively recently indicates that they managed to withstand the crisis that wiped out the super primate. Therefore, the comparison between them is valuable.

On the paleoecological side (that is, the description of what the ancient environment where both primates lived was like), the study confirms that there were significant changes in the vegetation of southern China over time. While, 2 million years ago, the environment was forested, dominated by different species of large trees, the situation changes considerably between 300,000 years and 200,000 years ago, which coincides with the “extinction window” estimated for the super monkey. The large areas of forest are now interrupted by areas of open vegetation, with much more grass.

Furthermore, the teeth of both species show that primates’ food and access to water were much better at the beginning of the period than at the time of extinction. Gigantopithecus. It is possible to estimate this based on layers in the teeth that have different chemical compositions as the animals grew. “We interpret this as something related to the presence of a wide diversity of foods and regular visits to water sources,” explains Westaway.

These layers become imprecise in the later period, which would indicate a drop in the diversity of foods accessible to animals. But the signs of this are much more serious in the case of the super primate, suggesting that it had more difficulty dealing with the scarcity of resources (which makes sense, considering its enormous size).

“This drop in food diversity would lead to chronic stress, which would possibly end up manifesting itself in changes in the offspring’s breastfeeding patterns, lower reproduction rates, malnutrition and difficulty in searching for food”, concludes the researcher. Although there were already archaic humans living in the region at this time, there is no evidence that they hunted the Gigantopithecus.