Fossils of ancient apes are even rarer than those of ancient humans, so very little is known about these important evolutionary missing links.
The most complete extinct-ape skull ever found reveals what the last common ancestor of all living apes and humans might have looked like, according to a new study.
"If you're a fossil finder, you know that look", he said.
Publication: Nengo, I., Tafforeau, P., Gilbert, C.C., Fleagle, J.G., Miller, E.R., Feibel, C., Fox, D., Feinberg, J., Pugh, K.D., Berruyer, C., Mana, S., Engle, Z.and Spoor, F. New infant cranium from the African Miocene sheds light on ape evolution. Researchers have found bits of jaw, facial bones and foreheads, but a complete cranium is an nearly miraculous find. Three specimens of note include a 25 million-year-old jawbone found in Tanzania (which technically falls outside the Miocene era), an 11 million-year old crushed skull of an ape known as Oreopithecus, and a 7 million-year-old ape skull with an intact braincase, belonging to the genus Sahelanthropus.
"Nyanzapithecus alesi was part of a group of primates that existed in Africa for over 10 million years", Nengo says, adding, "What the discovery of Alesi shows is that this group was close to the origin of living apes and humans and that this origin was African".
The 13-million-year-old infant skull, which its discoverers nicknamed "Alesi", was unearthed in Kenya in 2014. In a new study published today in Nature, a Stony Brook University research team led by Isaiah Nengo describe the almost complete skull, showing a number of adaptations that would go on to influence ape and human evolutionary histories. The species name is taken from the Turkana word for ancestor, "ales".
Most fossils from more than 40 known extinct ape species amount to no more than jaw fragments or a few isolated teeth.More news: Leaked iOS code reveals new details about the iPhone 8's home button
Analysis of this tiny skull shows that this ancient species was more monkey-like than it was ape-like.
"There was some discussion for a while about whether the modern apes actually originated in Africa or in Eurasia, because gibbons today live in Southeast Asia, and this pretty squarely confirms that the origin of apes was in Africa".
Much of the information the lemon-sized skull has provided scientists is the result of highly sensitive 3D X-ray imaging performed by the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. This technique revealed microscopic enamel layers that had formed daily from birth in developing adult teeth that yet to erupt. The skull is also so well-preserved that scientists were able to estimate that the creature died at about 16 months of age. These so-called hominoids - that is, the gibbons, great apes and humans - emerged and diversified during the Miocene epoch, approximately 23 million to 5 million years ago. If the animal was fully grown it would have weighed in at 25 pounds and looked like a gibbon. Modern gibbons are smaller apes and somewhat resemble monkeys, but they are tailless like other apes. So N. alesi was likely a slower-moving primate.
Alesi is now back in Kenya.Nengo said he plans to continue fieldwork there and also to use Alesi as "kind of an anchor" for the study of babies and the role of babies in the evolution of apes and humans.
"The living apes are found all across Africa and Asia - chimps and gorillas in Africa, orangutans and gibbons in Asia - and there are many fossil apes found on both continents, and Europe as well", study co-author Christopher Gilbert, a paleoanthropologist at Hunter College in NY, told Live Science. Ellen Miller, an anthropology professor at Wake Forest University, contributed to the study. Our species, Homo sapiens, appeared approximately 300,000 years ago in Africa.
The lemon-sized skull was discovered in Kenya by an worldwide team of researchers, and was dated to the middle of the Miocene era, a little-understood time when many species of ape arose in Africa, including common ancestors of both modern apes and humans. The only way to finally settle this debate once and for all is to find more fossil evidence, which, based on precedence, won't be easy.
Here's ESRF's video about the discovery of Nyanzapithecus alesi. "It was much older than that".