These 17-Million-Year-Old Fossils Could Rewrite the Evolutionary Tree of Apes—Including Humans
Jawbone fragments and teeth from a previously unknown species hint that the evolution of modern apes occurred in what’s now North Africa or the Arabian Peninsula, rather than in East Africa
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In 2024, a group of paleontologists journeyed into the dry, sandy desert of northern Egypt in search of fossils in a valley called Wadi Moghra. Scientists had previously found ancient monkey remains there, but the team hoped to be the first to find some from an ape.
Paleontologist Hesham Sallam of Mansoura University in Egypt was examining an odd piece of fossilized jawbone one day when Shorouq Al-Ashqar, also a paleontologist at the university, approached him with another mandible fossil.
“Dr. Hesham, we found an ape,” Al-Ashqar said to him at that moment, she recounts to National Geographic’s Tim Vernimmen.
Analyses of both jaw fragments and some teeth hint they belong to a previously unknown extinct species of ape called Masripithecus moghraensis, Al-Ashqar, Sallam and their colleagues report in a study published March 26 in the journal Science. It lived in northern Africa around 17 million to 18 million years ago during a time period called the early Miocene, and it hints that the evolution of modern apes may not have occurred in the region where it was long suspected.
Previous studies of the origins of apes have mainly focused on East Africa. The new discovery suggests that Masripithecus is distinct from creatures of the same age found in the more southern location, and that apes lived in the area around what’s now Egypt earlier than previously thought. What’s more, the newfound species closely resembles predictions of what the common ancestor of all modern apes, including humans, looked like.
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“We spent five years searching for this kind of fossil because, when we look closely at the early ape family tree, it becomes clear that something is missing—and North Africa holds that missing piece,” Sallam says in a statement.
The fossils were recovered from 17-million- to 18-million-year-old sediment, and their shapes hinted that they belonged to apes rather than monkeys. The jaws were strong and featured large canine and premolar teeth, along with rounded molars that had roughly textured chewing surfaces. The teeth are flatter and sized differently than those in monkeys, Al-Ashqar tells Science News’ Jake Buehler.
Additionally, this combination of mouth features hasn’t been seen in other apes from that time, and it suggests Masripithecus munched on a variety of foods and could adapt to new ones when climatic changes occurred.
“It likely depended mainly on fruits,” Al-Ashqar tells New Scientist’s James Woodford, “but could also process harder foods like nuts and seeds, especially with that robust jaw and complex molars.”
Need to know: Apes versus monkeys
Apes and monkeys’ last common ancestor lived an estimated 25 million years ago. Today, the main difference between these two groups is that most monkeys have tails, while apes lack them. Apes also have larger bodies, more advanced cognitive skills and longer arms compared to their legs than monkeys.
With the new fossils in hand, the researchers combined genetic data from living apes with fossil characteristics of extinct and modern species to create an evolutionary tree for Masripithecus. The work revealed that the new species is very closely related to the last common ancestor of all living apes, including gibbons, gorillas, chimpanzees, orangutans and humans. Further statistical analysis that predicted the migration of apes out of Africa supported this relationship and suggested that apes evolved in North Africa or the Arabian Peninsula, rather than East Africa, where researchers previously thought it happened.
“The entire story [of early ape evolution] was told by only a small corner of the continent,” Al-Ashqar tells Science News.
Going forward, scientists want to use this discovery as a jumping-off point to reconstruct apes’ evolutionary history beyond the area where their fossils have historically been most common.
“Almost everything we know from early Miocene apes comes from sites in East Africa, and then there are lots of apes known from middle Miocene sites in Eurasia,” Ellen Miller, a paleoanthropologist at Wake Forest University who was not involved in the study, tells National Geographic. “So the recovery of Masripithecus makes it tempting to draw arrows on maps.”
While the new find is exciting, there isn’t enough evidence to definitively rewrite the history of ape evolution, Miller says. “But a new find such as this is always the beginning of the work, not the end.”