An incredibly rare juvenile skull with an extinct ape has now been discovered in China, findings indicating that a very large group of apes once existed in South East Asia, according to researchers.
Apes are the closest relatives to humans, including gorillas, chimpanzees and orangutans. They once inhabited much of the Old World, including most of Europe and Asia, and a much larger swath of Africa than they do at present.
An extremely rare juvenile skull of an extinct ape that lived some 6 million years ago has now been revealed from China.
A crucial period in the evolution of humans and their ape relatives was around 5 million to 11 million years ago in the late Miocene era. In much of Eurasia, apes became extinct near the end of the Miocene.
“Climate and environments were changing rapidly throughout the world at the end of the Miocene, and these changes are reflected in the changing faunas, particularly in the Old World, where animals adapted to living in more equable forest habitats gave way in most places to those capable of living in more open habitats and drier, more seasonal conditions,” said researcher Jay Kelley, a paleoanthropologist at the Institute of Human Origins at Arizona State University in Tempe.
Cool cranium discovery
To explore ape evolution during the late Miocene, scientists investigated a site in the Yunnan province in southern China called Shuitangba, which is a mine for lignite, a form of low-grade coal. Southern China was less affected by the deteriorating climate during the late Miocene that drove extinct many ape species throughout the rest of Eurasia.
Miners have recovered fossils at Shuitangba since at least the 1950s. The investigators began excavating at the site in 2007. “The workers keep a lignite fire going all the time to roast potatoes, which is smoky and smells awful, and your hair and clothes become permeated with the lignite smell,” Kelley said.
The researchers now reveal the 6-million-year-old cranium of the extinct ape Lufengpithecus, a skull about 3 inches (8 centimeters) wide.
“It’s from a young juvenile — it would have been perhaps about 5 years old if its growth was like that of chimpanzees,” Kelley told LiveScience. “I suspect adults of this species would have been in the body size range of large chimpanzees, the larger males perhaps somewhat larger. We know from the developing canine teeth that our juvenile was a male.”
Back when these apes were alive, the area was fairly swampy — “warm or hot and wet for much of the year, even if there was some seasonality,” Kelley said. “We have also found a diverse array of birds associated with wetter environments, and mammals associated with wet environments such as beavers and otters. We have also uncovered the trunks of very large trees, so it was heavily forested.”
Learning about ape evolution
Skulls of fossil apes and other close relatives of humanity are extremely rare, especially those of infants and young juveniles. This find is only the second relatively complete cranium of a young juvenile from the Old World during the entire Miocene, an epoch stretching from 5 million to 23 million years ago.
The Shuitangba site in China, where an extremely rare juvenile skull of an extinct ape has now been revealed.
“The preservation of the new cranium is excellent,” Kelley said in a statement. “This is important because all previously discovered adult crania of the species to which it is assigned, Lufengpithecus lufengensis, were badly crushed and distorted during the fossilization process.”
In living species of apes, skulls at the same stage of development as the new fossil already closely resemble those of adults. “Therefore, the new cranium, despite being from a juvenile, gives researchers the best look at the cranial anatomy of Lufengpithecus lufengensis,” Kelley said.