An Ape Before Orangutans
In the lignite (soft coal) beds of Yunnan Province, paleontologists have unearthed thousands of fossils belonging to Lufengpithecus, an extinct ape that lived during the Late Miocene epoch. The genus spans a significant amount of time, with the oldest species, L. keiyuanensis, dating to between 10 and 11 million years ago. Other important fossil sites at Lufeng and Yuanmou have yielded remains from 6.2 to 8.2 million years ago. This ape lived when climates were cooling globally, causing the extinction of many ape species across Eurasia. Southern China, however, may have remained a warm and humid refuge, allowing this lineage to survive longer than its relatives elsewhere.
One of the most important discoveries is the crushed but nearly complete cranium of a juvenile Lufengpithecus lufengensis, found at a site called Shuitangba and dating to about 6.2 million years old. Juvenile ape skulls are exceptionally rare in the fossil record, making this find important for understanding the growth and appearance of this species. An adult Lufengpithecus likely weighed around 50 kilograms (110 lbs). Its teeth feature thick enamel and large molars, suggesting a diet that could handle tough foods, though studies point towards a preference for soft fruits and leaves.
A Puzzling Family Tree
The central scientific question surrounding Lufengpithecus is its place in the primate family tree. Many researchers consider it part of the subfamily Ponginae, which includes modern orangutans (Pongo) and their extinct relatives. This connection is based on general similarities in the teeth and jaws. However, the known skulls, including the well-preserved juvenile specimen, lack key anatomical features that definitively link them to orangutans.
This ambiguity has led to competing hypotheses. Some Chinese scientists point to features like a broad distance between the eyes and certain dental characteristics that are more reminiscent of hominines, the group that includes African apes and humans. Different analyses suggest Lufengpithecus may represent a distinct, late-surviving branch of Eurasian apes that left no living descendants. Another fossil ape from Thailand and Myanmar, Khoratpithecus, is now considered by many to be the closest known relative of orangutans, further complicating the status of Lufengpithecus. The debate continues as new analytical techniques and fossil discoveries emerge.