Orangutans (genus Pongo) are the closest living relatives of Gigantopithecus blacki, the biggest primate that ever walked the Earth, according to new research published in the journal Nature.
Welker et al demonstrated that Gigantopithecus blacki is a sister clade to orangutans with a common ancestor about 12-10 million years ago, implying that the divergence of the prehistoric primate from orangutans forms part of the Miocene radiation of great apes. Image credit: Ikumi Kayama, Studio Kayama LLC.
Gigantopithecus blacki is an extinct, giant hominid that once inhabited dense forests of Southeast Asia.
As the name suggests, the giant primate was larger than gorillas, standing up to 10 feet (3 m) and weighing up to 540 kg (1,200 lb).
It was first discovered by the German paleontologist Gustav von Koenigswald in 1935, when he described an isolated tooth that he found in a Hong Kong drugstore.
The entire fossil record of Gigantopithecus blacki — dated between the Early Pleistocene (about two million years ago) and the Middle Pleistocene (about 300,000 years ago) — includes thousands of teeth and four partial jaws from subtropical Southeast Asia.
All the locations at which the primate’s remains have been found are in or near southern China, stretching from Longgupo Cave, just south of the Yangtze River, to the Xinchong Cave on Hainan Island and, possibly, into northern Vietnam and Thailand.
“Previous attempts to understand which could be the living organism most similar to Gigantopithecus could only be based on the comparison of the shape of the fossils with skeletal reference material from living great apes,” said co-lead author Dr. Enrico Cappellini, a researcher at the Globe Institute at the University of Copenhagen.
“Ancient DNA analysis was not an option, because Gigantopithecus went extinct approximately 300,000 years ago, and in the geographic area Gigantopithecus occupied no DNA older than approximately 10,000 years has been retrieved so far.”
“Accordingly, we decided to sequence dental enamel proteins to reconstruct its evolutionary relation with living great apes, and we found that orangutan is Gigantopithecus’ closest living relative.”
To address the evolutionary relationships between Gigantopithecus blacki and living apes, Dr. Cappellini and colleagues retrieved dental enamel proteome sequences from a 1.9-million-year-old molar of the ancient primate found in Chuifeng Cave, China.
“By sequencing proteins retrieved from dental enamel about two million years old, we showed it is possible to confidently reconstruct the evolutionary relationships of animal species that went extinct too far away in time for their DNA to survive till now,” Dr. Cappellini said.
“We can even conclude that the lineages of orangutan and Gigantopithecus split up about 12 million years ago.”
“The analysis revealed that Gigantopithecus blacki belongs to the same clade as the orangutan, its closest living relative, although its separation with the current orangutans is very distant, which explains the previous confusion in the field,” said co-lead author Dr. Tomas Marques-Bonet, a scientist at the University Pompeu Fabra, Barcelona.
“Both soon diverged in the Miocene — more than 10 million years ago — but they certainly shared a common ancestor.”
“Primates are relatively close to humans, evolutionary speaking,” said first author Dr. Frido Welker, a postdoctoral researcher at the Globe Institute at the University of Copenhagen.
“With this study, we show that we can use protein sequencing to retrieve ancient genetic information from primates living in subtropical areas even when the fossil is two million years old.”
“Until now, it has only been possible to retrieve genetic information from up to 10,000-year-old fossils in warm, humid areas.”
_____
F. Welker et al. Enamel proteome shows that Gigantopithecus was an early diverging pongine. Nature, published online November 13, 2019; doi: 10.1038/s41586-019-1728-8
