3 meter tall apes in East Asia became extinct because they were overspecialized

In the spectacular karst landscapes of southern China, giant apes, known as Gigantopithecus blacki, once roamed. They were three meters tall and weighed about 250 kilograms. They became extinct about 300 thousand years ago. The reasons for the extinction of these apes remained a mystery for years

In the spectacular karst landscapes of southern China, giant apes, known as Gigantopithecus blacki, once roamed. These monsters, which were three meters tall and weighed about 250 kilograms, are considered distant relatives of man. Although they became extinct before humans settled in the area, the reasons for the extinction of these great apes remained a mystery for years. The only evidence of their existence are about 2000 fossilized teeth and four jaw bones.

New findings from this area, published in the journal Nature, and revealed by a joint research team of researchers from China, Australia and the USA, prove without a doubt that the largest primate that walked the earth became extinct between 295,000 and 215,000 years before our time, when it was unable to adapt his food preferences and behaviors to the environmental changes, and remained exposed to the climate changes that carved his destiny.

"The story of G. blacki is a puzzle in the field of paleontology - how could such a huge creature become extinct while other primates adapted and survived? The unsolved cause of its disappearance has become the 'holy grail' of this field," says paleontologist and co-lead author Professor Yingchi Zeng of the Institute of Mammalian Paleontology and Anthropology at the Chinese Academy of Sciences (IVPP).

"The IVPP has been digging for evidence of the existence of G. blacki in this area for over a decade, but without accurate dating and consistent environmental analysis, the cause of its extinction has been lost sight of."

A comprehensive research project

The definitive proof that reveals the story of the great ape's extinction came from a major project involving the collection of evidence from 22 cave sites throughout Guangxi Province in southern China. The basis of the study was dating.

"It is a rare feat to present a definite cause for the extinction of a species, but determining the exact time at which a species disappeared from the fossil record gives us a focused time domain for environmental reconstruction and behavioral assessment," says co-lead author, Macquarie University geochronologist Professor Kira Westaway. "Without solid dating, we're just looking for clues in the wrong places."

Six Australian universities joined the project. Macquarie University, Southern Cross University, University of Wollongong and University of Queensland used a number of techniques to date samples. Southern Cross University researchers also mapped G. blacki teeth to extract information about the monkeys' behaviors. Flinders University researchers studied the pollen and sediment containing fossils in the cave respectively, to reconstruct the environments in which G. blacki thrived and then disappeared.

Dating techniques and environmental analysis

Six different dating techniques were applied to the cave sediments and fossils, yielding 157 radiometric ages. They were used together with eight sources of environmental and behavioral findings, and were applied to 11 caves containing remains of G. blacki, and also to 11 caves of a similar age range where no remains of G. blacki were found. blacki.

The main technique the researchers used was luminescence dating, which measures the light-sensitive signal found in the sediments that surrounded the G. blacki fossils, aided by uranium series (US) dating and electron spin resonance (US-ESR) of the G. blacki teeth themselves.

"Direct dating of the fossil remains confirmed their age corresponding to the luminescence series in the sediments in which they were found, giving us a comprehensive and reliable chronology for the extinction of G. blacki," says Southern Cross University geochronologist Professor Renaud Juan-Boyeau.

Insights from dental surgery

Through a detailed analysis of pollen, reconstructions of animals that lived at that time, stable isotope analysis of the teeth, and detailed microscopic analysis of the sediment in the cave - the group revealed the environmental conditions that led to the extinction of G. blacki. Then, using trace element analysis and tooth erosion textural analysis (DMTA), the team modeled the behavior of G. blacki while it thrived, compared to the time of the species' extinction. The findings show that G. blacki became extinct between 295,000 and 215,000 years BC, much earlier than previously thought. Before this time, G. blacki thrived in a rich and diverse forest.

Environmental changes and comparative adaptation

Approximately between 700,000 and 600,000 years before our time, the environment became more variable due to the strengthening of the seasons, which caused a change in the composition of the forest species diversity.

Orangutans (genus Pongo) – a close relative of G. blacki – adapted their size, behavior and habitat preferences as conditions changed. Unlike them, G. blacki relied on a less nutritious alternative food source when its preferences were unavailable, reducing its food variety. The monkey became less mobile, with a limited geographic range for gathering food, and encountered ongoing ecological pressures and a decline in the number of individuals in the population.

"G. blacki was the absolute specialist, compared to the more flexible adaptors, such as the orangutans, and this ultimately led to its extinction," says Professor Zeng.

Professor Vestaway says: “With the threat of a Friday mass extinction event looming over us, there is an urgent need to understand why species are becoming extinct.

"Investigating the causes of unresolved past extinctions gives us a good starting point for understanding the resilience of primates and the fate of other large animals, past and future."

Dealing with the mystery of the extinction of the giant ape, Gigantopithecus blacki, provides us with a rare opportunity to learn about dealing with environmental changes and their effects on different species. This study, published in Nature, provides a glimpse not only into the distant past, but also warns of the potential dangers that may threaten species in the present and future, while emphasizing the importance of understanding these processes to maintain biodiversity.

More of the topic in Hayadan:

• Homo habilis (probably) was here
• Eternal bonds: Great apes exhibit remarkable memory for their long-lost friends
• Remains of "primitive man" have been discovered, exhibiting human characteristics alongside those of apes
• A 47-million-year-old fossil may be the common ancestor (or common mother) of today's humans and apes
• A researcher warns of the rapid extinction of the orangutan