Six new fossil species form 'snapshot' of primates stressed by ancient climate change

May 5, 2016, University of Kansas
A left lower jaw of Yunnanadapis folivorus, one of six new fossil species found in southern China. Credit: University of Kansas

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.

These primates eked out an existence just after the Eocene-Oligocene transition, some 34 million years ago. It was a time when drastic cooling made much of Asia inhospitable to primates, slashing their populations and rendering discoveries of such fossils especially rare.

"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."

The Eocene-Oligocene transition (EOT) functioned as a critical filtering episode during the evolutionary history of primates. Comparing the composition of the early Oligocene primate faunas from Asia reveals that surviving this Eocene-Oligocene evolutionary filter entailed a high degree of taxonomic and ecological selectivity: later Eocene primate assemblages tend to be dominated, both in terms of taxonomic richness and numerical abundance, by stem anthropoids, whereas the Oligocene primate tend to be dominated by lemur-like strepsirrhine primates. A similar comparison of the late Eocene-early Oligocene primates from Afro-Arabia shows a very different pattern of selectivity in response to the EOT: very few strepsirrhine primates survived the EOT, whereas anthropoids diversified both taxonomically and ecologically. The divergent responses shown by Afro-Arabian and Asian primates across the EOT evolutionary filter constrained the subsequent course of primate macroevolutionary pattern across the Old World. Africa became the geographic nexus of anthropoid evolution, whereas Asia shows a strong break between Paleogene and Neogene anthropoid assemblages. Credit: Xijun Ni

The paper is the product of a decade's worth of fieldwork at a site in southern China, where the primates likely sought warmer temperatures. Beard and his colleagues Xijun Ni, Qiang Li and Lüzhou Li of the Chinese Academy of Sciences' Institute of Vertebrate Paleontology and Paleoanthropology describe the six new species from jaw and tooth fragments, which survived the ages due to their tough enamel surfaces and serve as "fingerprints" to identify ancient animals.

"The usually gives you a snapshot here or there of what ancient life was like. You typically don't get a movie," Beard said. "We have so many primates from the Oligocene at this particular site because it was located far enough to the south that it remained warm enough during that cold, dry time that primates could still survive there. They crowded into the limited space that remained available to them."

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.

Credit: Xijun Ni

"If you look back at the fossil record, we know that tarsiers once lived on mainland Asia, as far north as central China," Beard said. "The fossil teeth described in this paper are nearly identical to those of modern tarsiers. Research shows that modern tarsiers are pretty much living fossils—those things have been doing what they do ever since time immemorial, as far as we can tell."

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 today, are more sensitive to a changing climate than other mammals."

Explore further: New species of early anthropoid primate found amid Libyan strife

More information: "Oligocene primates from China reveal divergence between African and Asian primate evolution," Science, DOI: 10.1126/science.aaf2107

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13 comments

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jyro
1 / 5 (16) May 05, 2016
The climate never quits changing on Earth, 4.5 billion years of change.
torbjorn_b_g_larsson
5 / 5 (13) May 06, 2016
... but it has never changed as dangerously rapidly as today, when we humans force the change.
viko_mx
1 / 5 (12) May 07, 2016
Does the religiuos evolutionist which desparately trying to justify their lawlesness with modern mithologies know how forms the fossils and what results they obtain when trying to mesure the age of different fossils?
torbjorn_b_g_larsson
5 / 5 (13) May 07, 2016
@viko: Science like biology or geochronology is useful precisely because it relies on fact, not religious fantasy. The article is self explanatory why speciation, fossils and geochronology dating of them and of the climate is truthful and consistent. Also here: https://en.wikipe...volution , https://en.wikipe.../Fossil, https://en.wikipe...ronology .

Knowing how to spell is also useful. So is knowing how to put meaningless trolls on the "ignore" list: done. Bye.
viko_mx
1 / 5 (11) May 07, 2016
I do not like declarations but scientific explanations. Please explain this facts. Lets focus on details.

How can be formed the fossils and how can be measured their real age by scientific (not shamanic) methods?
huckmucus
4.6 / 5 (10) May 07, 2016
The process of fossilization is akin to the process of teaching some people. And the end result is just as beautiful, rare and hard to understand; especially for all the bone (heads) that don't make it.
torbjorn_b_g_larsson
5 / 5 (13) May 07, 2016
Are you talking to me?

"How can be formed the fossils and how can be measured their real age by scientific (not shamanic) methods?"

I already linked to those explanations, you dolt! That wasn't a declaration, but a scientific explanation of your behavior from making a testable prediction and then observing your inane question. (There aren't any stupid questions but those who repeats despite having been given the answer.)

Please stop breaking the rule of "ignore filters", I wouldn't have known about your addressing me except that I suspecyed it and clicked on "show comment". Which obviously was the waste of time I also suspected. :-/
viko_mx
1 / 5 (10) May 08, 2016
?torbjorn_b_g_larsson

Why you are lying? Where I or somebody else can read your personal scientific explanations for the question how can be formed the fossils and how can be measured their real age by scientific (not shamanic) methods?

If you have scientific answers to these questions it would be not difficult to you to give them. But you do not and as a consequence try to escape from responsibility by giving me a useless link to waste my time.
MalleusConspiratori
3.6 / 5 (15) May 08, 2016
jyro's the kind of sociopath that would steal a car from a car park and offer the defense that, "Cars come and go from here all the time. Look. In and out. Constantly. Why are you looking for an exceptional explanation? Why are you blaming me?" And he'd believe it. This is where the gen X/millennial sociopath is different than the older variety. The older variety knew when they were lying. These newer ones have so many justifications and reasons for why that's OK that they're capable of scamming themselves as much as the gullible.

canthink, antisciencegorrilla and viko_mx wouldn't be aware of intellectual integrity if it crawled up their nose and did the tango!
torbjorn_b_g_larsson
5 / 5 (7) May 08, 2016
"Why you are lying?"

Where am I lying?

"your personal scientific explanations".

Now you are changing subject, you never asked for that. What I have is _the_ scientific explanations, which I linked to, science is not a personal opinion but facts and descriptions everyone (can) agree on.

Look, I see that you don't understand what science is, but you have the arrogance not to ask for help, and to make claims on a subject you know nothing about.

Back to school with you, is the best suggestion I have to resolve your personal problem.
HeloMenelo
3.4 / 5 (8) May 09, 2016
Does the religiuos evolutionist which desparately trying to justify their lawlesness with modern mithologies know how forms the fossils and what results they obtain when trying to mesure the age of different fossils?

can a no brain bafoon aka antigorcle sockpuppet grow a brain ?
HeloMenelo
3.3 / 5 (7) May 09, 2016
The climate never quits changing on Earth, 4.5 billion years of change.


aaa.. antigoricle sock jiro illustrated in the article's picture above... no wonder all his socks are popping up in the coment section, it's bannana feeding time... :D
AlbertPierrepointOBE
2.1 / 5 (9) May 10, 2016
Deniers hate the concept of climate change because it shows up that a mindless system is capable of something they never will be able to pull off.

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