Six new fossil species form 'snapshot' of Asian primates stressed by ancient climate change
In a study to be published this week in the journal Science, researchers describe unearthing a "mother lode" of a half-dozen fossil primate species in southern China.
|One of the fossil species, which the research team has named Oligotarsius rarus, is “incredibly similar” |
to the modern tarsier found today only in the Philippine and Indonesian islands
[Credit: Andrew Cunningham]
"At the Eocene-Oligocene boundary, because of the rearrangement of Earth's major tectonic plates, you had a rapid drop in temperature and humidity," said K. Christopher Beard, senior curator at the University of Kansas' Biodiversity Institute and co-author of the report. "Primates like it warm and wet, so they faced hard times around the world -- to the extent that they went extinct in North America and Europe. Of course, primates somehow survived in Africa and Southern Asia, because we're still around to talk about it." Because anthropoid primates -- the forerunners of living monkeys, apes and humans-- first appeared in Asia, understanding their fate on that continent is key to grasping the arc of early primate and human evolution.
"This has always been an enigma," Beard said. "We had a lot of evidence previously that the earliest anthropoids originated in Asia. At some point, later in the Eocene, these Asian anthropoids got to Africa and started to diversify there. At some point, the geographic focal point of anthropoid evolution -- monkeys, apes and humans -- shifted from Asia to Africa. But we never understood when and why. Now, we know. The Eocene-Oligocene climate crisis virtually wiped out Asian anthropoids, so the only place they could evolve to become later monkeys, apes and humans was Africa."
|A left lower jaw of Yunnanadapis folivorus, one of six new fossil species found in southern China |
[Credit: University of Kansas]
Like most of today's primates, the KU researcher said the ancient Chinese primates were tropical tree-dwellers. One of the species, which the research team has named Oligotarsius rarus, was "incredibly similar" to the modern tarsier found today only in the Philippine and Indonesian islands.
Beard said that if not for the intense global cooling of the Eocene-Oligocene transition, the main stage of primate evolution may have continued to be in Asia, rather than transitioning to Africa where Homo sapiens eventually emerged. Indeed, the team's findings underscore a vulnerability to climate change shared by all primates.
"This is the flip side of what people are worried about now," he said. "The Eocene-Oligocene transition was the opposite of global warming -- the whole world was already warm, then it cooled off. It's kind of a mirror image. The point is that primates then, just like primates today, are more sensitive to a changing climate than other mammals."
Source: University of Kansas [May 05, 2016]