New primate fossil suggests Asian, not African, origins for human ancestors
Early ancestors of monkeys, apes, and even humans started life in Asia, and not Africa as it has long been thought, according to a new fossil discovery in Myanmar.
An international team of researchers announced the discovery of Afrasia djijidae, a new fossil primate that closely resembles another early anthropoid, Afrotarsius libycus, which is of a similar age and was discovered in the Sahara in Libya. The resemblance, says the team, is a sign that early anthropoids colonized Africa, setting the stage for later ape and human evolution. The scientific paper describing the discovery appears in Proceedings of the National Academy of Sciences.
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This latest discovery is joined by a host of other fossils, recently found throughout China, Myanmar and other Asian countries, as evidence that overturns previously held notions of an African starting point for primate evolution.
"Not only does Afrasia help seal the case that anthropoids first evolved in Asia, it also tells us when our anthropoid ancestors first made their way to Africa, where they continued to evolve into apes and humans," says Chris Beard, Carnegie Museum of Natural History paleontologist and member of the discovery team that also included researchers from Myanmar, Thailand, and France.
In 2005, Beard and an international team of researchers sifting fossils of early fish, turtle, and ancestral hippo teeth from fossil beds near the village of Nyaungpinle in Myanmar found a molar the size of a kernel of popcorn. The tooth, dated to about 38 million years ago, belonged to a new species of ancient primate, which would have been the size of a small chipmunk, reports Science Now.
It took six more years for the team to collect four molars from the species, but that was enough to identify Afrasia's relation to Afrotarsius. When the researchers examined the teeth from the two primates under a microscope, they were so similar in size, shape, and age that they could have belonged to the same species of primate, Beard tells Science Now.
Mammalian teeth have a complicated structure which can act like a fingerprint for paleontologist to reconstruct how extinct species relate to one another. The close similarities between Afrasia and Afrotarsius link the two fossils to the same time period, because if these Asian anthropoids had arrived in Northern Africa any earlier, differences may have evolved that would show up in the fossil record.
It is still unknown how early anthropoids migrated from Asia to Africa, but any remaining in Asia most likely died out.
"Around 34 million years ago, there was a dramatic glacial event that cooled the world climate and affected Asia more than Africa. During that crisis, we suppose that all primitive Asian anthropoids disappeared," researcher Jean-Jacques Jaeger, a paleontologist at the University of Poitiers in France, told LiveScience.
Not only does this finding offer insight into our true origins, it gives researchers a clearer picture of the timing of Afrasia's trek to Africa.
"For years we thought the African fossil record was simply bad," said Jaeger. "The fact that such similar anthropoids lived at the same time in Myanmar and Libya suggests that the gap in early African anthropoid evolution is actually real. Anthropoids didn't arrive in Africa until right before we find their fossils in Libya."
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