53 million-year-old high Arctic mammals wintered in darkness

53 million-year-old high Arctic mammals wintered in darkness
A hippo-like mammal known as Coryphodon was one of several ancient mammal groups that endured twilight winters in the high Arctic 53 million year ago, according to a new study led by the University of Colorado at Boulder. Credit: Image copyright American Museum of Natural History/D. Finnin.

(PhysOrg.com) -- Ancestors of tapirs and ancient cousins of rhinos living above the Arctic Circle 53 million years ago endured six months of darkness each year in a far milder climate than today that featured lush, swampy forests, according to a new study led by the University of Colorado at Boulder.

CU-Boulder Assistant Professor Jaelyn Eberle said the study shows several varieties of prehistoric as heavy as 1,000 pounds each lived on what is today Ellesmere Island near Greenland on a summer diet of flowering plants, deciduous leaves and aquatic vegetation. But in winter's twilight they apparently switched over to foods like twigs, leaf litter, evergreen needles and fungi, said Eberle, curator of fossil vertebrates at the University of Colorado Museum of Natural History and chief study author.

The study has implications for the dispersal of early mammals across polar land bridges into North America and for modern mammals that likely will begin moving north if Earth's climate continues to warm. A paper on the subject co-authored by Henry Fricke of Colorado College in Colorado Springs and John Humphrey of the Colorado School of Mines in Golden appears in the June issue of Geology.

The team used an analysis of carbon and oxygen isotopes extracted from the fossil teeth of three varieties of mammals from Ellesmere Island -- a hippo-like, semi-aquatic creature known as Coryphodon, a second, smaller ancestor of today's tapirs and a third rhino-like mammal known as brontothere. Animal teeth are among the most valuable fossils in the high because they are extremely hard and better able to survive the harsh freeze-thaw cycles that occur each year, Eberle said.

Telltale isotopic signatures of carbon from enamel layers that form sequentially during tooth eruption allowed the team to pinpoint the types of plant materials consumed by the mammals as they ate their way across the landscape through the seasons, Eberle said.

"We were able to use carbon signatures preserved in the tooth enamel to show that these mammals did not migrate or hibernate," said Eberle. "Instead, they lived in the high Arctic all year long, munching on some unusual things during the dark winter months." The study was funded by the National Science Foundation.

53 million-year-old high Arctic mammals wintered in darkness
University of Colorado at Boulder Assistant Professor Jaelyn Eberle, left, searches for early mammal fossils in the high Arctic with Brendan Postnikoff of the University of Saskatchewan (blue parka) and Joe Kudlack, right, from Banks Island in the Northwest Territories. Credit: Image courtesy University of Colorado

An analysis of from the fossil teeth helped determine seasonal changes in surface drinking water tied to precipitation and temperature, providing additional climate information, said Eberle. The results point to warm, humid summers and mild winters in the high Arctic 53 million years ago, where temperatures probably ranged from just above freezing to near 70 degrees Fahrenheit, Eberle said.

The environment on central Ellesmere Island, located at about 80 degrees north latitude, was part of a much larger circumpolar Arctic region at the time, she said. It probably was similar to swampy cypress forests in the southeast United States today and still contains fossil tree stumps as large as washing machines, Eberle said.

On central Ellesmere Island in today's high Arctic -- a polar desert that features tundra, permafrost, ice sheets, sparse vegetation and a few small mammals -- the temperature ranges from roughly minus 37 degrees F in winter to 48 degrees F in summer and is the coldest, driest environment on Earth. There is sunlight in the high Arctic between October and February, and the midnight sun is present from mid-April through the end of August.

The year-round presence of mammals such as the hippo-like Coryphodon, tapirs and brontotheres in the high Arctic was a "behavioral prerequisite" for their eventual dispersal across high-latitude land bridges that geologists believe linked Asia and Europe with North America, Eberle said. Their dietary chemical signatures, portly shapes and fossil evidence for babies and juveniles in the Arctic preclude the idea of long, seasonal migrations to escape the winter darkness, she said.

"In order for mammals to have covered the great distances across land bridges that once connected the continents, they would have required the ability to inhabit the High Arctic year-round in proximity to these land bridges," Eberle said.

Instead, the animals likely made their way south from the Arctic in minute increments over millions of years as the climate shifted. "This study may provide the behavioral smoking gun for how modern groups of mammals like ungulates -- ancestors of today's horses and cattle -- and true primates arrived in North America," said Eberle, also an assistant professor in CU-Boulder's geological sciences department.

The surprising menagerie of Arctic creatures during the early Eocene epoch, which lasted from roughly 50 million to 55 million years ago, first became evident in 1975 when a team led by Mary Dawson of the Carnegie Museum of Natural History in Pittsburg discovered alligator jaw bones. Since then, fossils of aquatic turtles, giant tortoises, snakes and even flying lemurs -- one of the earliest forms of primates -- have been found on Ellesmere Island, said Eberle.

The new Geology study also foreshadows the impacts of continuing global warming on Arctic plants and animals, Eberle said. Temperatures in the Arctic are rising twice as fast as those at mid-latitudes as greenhouse gases build up in Earth's atmosphere from rising fossil-fuel burning, and air temperatures over Greenland have risen by more than 7 degrees F since 1991, according to climate scientists.

"We are hypothesizing that lower-latitude mammals will migrate north as the temperatures warm in the coming centuries and millennia," she said. If temperatures ever warm enough in the future to rival the Eocene, there is the possibility of new intercontinental migrations by mammals."

Because the oldest known tapir fossils are from the Arctic, there is the possibility that some prehistoric mammals could have evolved in the circumpolar Arctic and then dispersed through Asia, Europe and North America, said Eberle. "We may have to re-think the world of the early Eocene, when all of the Arctic land masses were connected in a supercontinent of sorts," she said.

Source: University of Colorado at Boulder (news : web)


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Jun 01, 2009
"-- Ancestors of tapirs and ancient cousins of rhinos living above the Arctic Circle 53 million years ago endured six months of darkness each year in a far milder climate than today that featured lush, swampy forests, according to a new study led by the University of Colorado at Boulder. "

Dang ol' global warming . . .

Jun 01, 2009
What! no ice! Don't tell Al.

Jun 01, 2009

"There is sunlight in the high Arctic between October and February,"

proof reading anyone?

Jun 02, 2009
The year-round presence of mammals such as the hippo-like Coryphodon, tapirs and brontotheres in the high Arctic was a "behavioral prerequisite" for their eventual dispersal across high-latitude land bridges that geologists believe linked Asia and Europe with North America, Eberle said.

There's something I'm not getting here. If the world's temperatures were much higher 53 million years ago then the sea levels would have would also have been much higher. Therefore no land bridge (or ice bridge) across the Bering Strait/North Atlantic? Therefore no large land animal migration?

Jun 02, 2009
A lot can happen in 10 years, let alone several million years. There were over 140 periods of substantial glaciation from that point until the mammalian migration.
I don't get your comment either.
You can't have a "year-round behavioural prescence prerequisite for migration" in the Arctic, and low sea levels at the same time.

Jun 02, 2009
These hippo-like and rhino-like animals might have been accustomed to the darkness of an Arctic winter but they still have to feed. If the sea levels are low enough for a land bridge to form then the Bering Strait would have been glaciated all year round.

Only if the North American plate was located further south in the Eocene would these animals have been able to cross over. But if that was indeed the case then the warm period detailed in the article would have been unnecessary for the migration.

The article gives me the impression that they're arguing that the animals were living all the year round in the Arctic in the especially warm period, and then as the temperatures lowered migrated slowly down into North America, which I'm saying couldn't happen. In the warm period the Sea blocks their path, in the cold periods the Ice.
Instead, the animals likely made their way south from the Arctic in minute increments over millions of years as the climate shifted. "This study may provide the behavioral smoking gun for how modern groups of mammals like ungulates -- ancestors of today's horses and cattle -- and true primates arrived in North America," said Eberle.

Jun 02, 2009
When the temperatures are high enough to allow these animals to feed in the Arctic, the sea levels are too high for them to migrate across the Bering Strait - so the western path is definitely cut off.

Only if the continents of Europe and North America were joined together (as they suggest in the last paragraph of the article) could the animals make the crossover from the East. But this completely contradicts the model of tectonic plates that the geologists have compiled. See this animation (16.7MB)

http://www.ucmp.b...l1_4.avi

53 million years ago according to this animation Europe and America were hundreds of miles apart. Enough said.

Jun 03, 2009
OK then, forget the 53 mya figure.

When it gets very warm the animals in Siberia, say, can live in the arctic all year round. Because it's very warm there is water in the Bering Strait. The animals stay in northern Siberia. Then gradually it gets colder, the animals move out of the Arctic because they cannot feed off ice. They are still in Siberia. Eventually it gets so cold that sea levels fall so low that there is a land bridge over the Bering Strait. Before the sea levels got to be so low, the Arctic ice cap has grown to cover the Strait with thousands of feet of ice. The animals are now in southern Siberia. No inter-continental migration.

Warm period - blocked by sea
Cold period - blocked by ice
Bering Strait impassable *at any time* for these kinds of animals.

"We are hypothesizing that lower-latitude mammals will migrate north as the temperatures warm in the coming centuries and millennia," she said. If temperatures ever warm enough in the future to rival the Eocene, there is the possibility of new intercontinental migrations by mammals."
She's dreaming.

Jun 03, 2009
I certainly don't see any connection between this and AGW. Who knows what natural elements were in the atmosphere 53 million years ago that could have created a warmer Earth? And the Earth can become extremely hot when all the Milankovitch cycles are in their non-glacial stages. (currently, precession is in a glacial stage and will be so for another 6000 years)


Jun 04, 2009
(currently, precession is in a glacial stage and will be so for another 6000 years)
No, no it isn't. If anything, we're entering one, not in one.

Opps. I meant to say that precession has been glacial for 6000 years and still has several thousand years to go.
http://en.wikiped...h_cycles

The last time all Milankovitch cycles were in non glacial stage was aprox 125,000 years ago. That is NOT the case now.

Jun 04, 2009
[Yes, however, Milankovich cycles aren't reliable due to the problems with correlation due to a lack of reliable data, as well as the various problems in calculation. They're an acceptable rough guide, but actual trending will rely on a connection between milankovich cycles and additional possible forcings.




So what difference does it make if it is off by 1000 years or so? Precession is still currently in it's glacial stage. It's still impossible for our orbit to be the cause of current climate change. If you are trying to make that claim anyway then you are making the claim that we are getting more heat from the sun. That excess shortwave radiation would be VERY easily detected. Co2 is the only thing left.

Jun 04, 2009
Because if it's off by 1000years the statement "Precession is still in X stage" isn't accurate. There is no causality and no commonality.




Not when it lasts over 20,000 years and we are only 6000 years into it.





Ptolemy had the orbits of most planets off by only a few arc lengths, does that mean we should still be saying that the Earth is the center of the solar system?








That dosn't make any sense. That was 1900 years ago. Science advanced just a bit since then.











Actually it appears we were getting more heat from the Sun during the periods with the most pronounced warming. The sun is fairly erratic.
impossible











It was easily detected,




It most certainly was not. (not at the levels hot enough to cause the current climate change)







http://lwf.ncdc.n...html#q10

Jun 04, 2009
[
*As long as you ignore plate tectonics, cosmic radiation, water vapor, diffusion, refraction, aerosols, methane, water upwelling, thermodynamic wind shifts, glacial advances, biomaterial decay, solar irradiance, intrasolar dust, solar invariance, the Urban Heat island effect, atmospheric seeding, high altitude ice crystal formation, nitrogen trifluoride, pending magnetic reversal, orbital variation, orbital decay, lunar orbital variation, lunar orbital decay, land use changes, deforestation, electromagnetic core flux, and a whole host of other unstudied phenomina.


As long as you believe junk science funded by greedy oil companies
http://www.exxposeexxon.com/

Jun 05, 2009
As long as you believe junk science funded by greedy oil companies
http://www.exxposeexxon.com/

One theme propaganda site. The IPCC and pro-AGM supporters are financed by $billions of tax payers money. A few millions to research science to find what is causing climate change as opposed to billions to try to show that Man is the cause.

Jun 05, 2009

Ok then, we're done here.

You were done when you lied about incoming solar heat.

Jun 05, 2009

One theme propaganda site. The IPCC and pro-AGM supporters are financed by $billions of tax payers money. A few millions to research science to find what is causing climate change as opposed to billions to try to show that Man is the cause.


The fact that oil companies have been funding junk science is pretty old news

http://www.exxposeexxon.com/&q=oil companies funding junk science&btnG=Google Search&aq=f&oq=&aqi=/

Just like the tobacco industries once did.







Jun 06, 2009
Land bridge? These animals didn't need a land bridge.

'Aliens' picked these critters up and simply dropped them off in a new location when they were done with them. This was all a part of their research. The 'aliens' wanted to see how the animals would adapt in a different environment.


Jun 06, 2009
I can't help but wonder if you deem it impossible for there to have been intercontinental migrations simply because you're caught up on the word "Arctic." This is what we call it today, because it is indeed "arctic." The Earth was much warmer 53 mya, which has been stated over and over. First, winters being just around freezing at their coldest would not cause large amounts of ice formation. Second, these animals didn't just decide one night to migrate, it was accomplished slowly, the climate slowly changing as they moved. As there are no eyes or brains left to study, these animals could have also had eye sight similar to that of cats. That, we'll never know unless someone invents a time machine. I'm not any kind of scientist but it just seems logical to me. The aliens could be our best bet though.

Jun 11, 2009


The sun isn't static, sorry to break your theoretical framework with those horrible things we call facts.

I never said it was static. You just now brought it up to try to hide your lie that excess heat from the sun is the cause of the current climate change.

Jun 11, 2009
Let's cut to the chase. Post a source that says excess heat from the sun is the cause of global warming.

Jun 12, 2009

Actually it appears we were getting more heat from the Sun during the periods with the most pronounced warming. The sun is fairly erratic.

It was easily detected, it allowed us to revise the idea that there was a solar constant into a solar average.


Back it up or shut it up!

Jun 14, 2009
What kind of crap is that? Show a link that proves massive amounts of incoming solar radiation. You can't do that because it is NOT happening. If it were you should easily be able to produce a NASA link with the satellite info.

Jun 14, 2009
But instead NASA says solar irradiance is down.

http://data.giss....Fig4.gif

Jun 14, 2009
If the change is TOO small (which has been the case for a very long time) then it makes very little difference.

Jun 15, 2009
The contribution of direct solar irradiance forcing is small compared to the greenhouse gas component. Not to mention that when solar forcing is doing the warming, the effects are localized. Have a look at the last interglacial period:
http://www.ncdc.n...ial.html

Jun 15, 2009
Here is probably the easiest explination of the GE:

http://www.epa.go...use.html

Jun 15, 2009
The biggest natural change is from Earth's orbit. It creates localized warming over a period of several thousand years. The localization varries throughout the centuries during an IP. In the past million and a half years, the Earth has not warmed as much as it has today. If it had the iron breathing lifeforms would have not been found. They would have spilled into the ocean if the ice had melted. But only NOW has the ice melted enough to make the discovery.

http://www.indepe...966.html


Jun 17, 2009
As to your question, localized warmring were the results

http://www.ncdc.n...ial.html

So I ask you, were is NOAA in error?

Jun 18, 2009
Precession is the Earth's slow wobble as it spins on axis. This wobbling of the Earth on its axis can be likened to a top running down, and beginning to wobble back and forth on its axis. The precession of Earth wobbles from pointing at Polaris (North Star) to pointing at the star Vega.

When Northern Hemisphere summers are coolest (farthest from the Sun due to precession and greatest orbital eccentricity) and winters are warmest (minimum tilt), snow can accumulate on and cover broad areas of northern America and Europe.

http://www.homepa...nkov.htm

Jun 18, 2009
Yes they eventually cause changes globally over the entire period. But not all at the same time. a few thousand years in the north and then the south. Since warming is occuring globally, the orbits cannot possibly be the blame.

Jun 18, 2009
The explination above is pretty simple. Yes the orbits do effect the entire globe. But only one hemisphere at a time. (one of the things that makes orbital forcings and greenhouse effect forcing completly different) The "wobble" effect moves the Earth to different positions. No the heat does not travel from the south to the north as you put it.

Jun 18, 2009
During the time when precession is warming one hemisphere, there is no pronounced effect in the other hemisphere.

Jun 18, 2009

So you're saying "There is no mechanic supporting thermal transport between the northern and southern hemispheres"?

Not enough to cause something like significant polar ice melt in one hemisphere when it is occuring in the other. (when calculating the orbital effects) You just don't understand how the greenhouse effect works. A lot of the heat will escape into space during an interglacial peak if there is no pronounced amounts of greenhouse gasses to trap the heat and therefore will have little effect on the opposite hemisphere.

Jun 19, 2009
Yes the Co2 is a very small number. That's no excuse to deny global warming and a very ignorant statement in any scientific study.

Jun 20, 2009
No I won because of your "less than 1%" comment. If we go by your line of thinking then black widow spiders should be harmless since a man is so much bigger than one. Or what about an actual greenhouse? (the plastic ones) Look at how thin the plastic is. I know you oil cronies feel you need to spread your lies like the tobacco companies once did, but just how stupid do you think the average person is?

Jun 22, 2009

Dumb enough to believe that the petatons of water vapor released by man has a smaller effect than the gigtons of CO2.


No! Only you seem to follow the theory of "Oh! It's so small so it can't be tangable." That kind of ideology has no place in the scientific community.

Jun 23, 2009
You don't even understand 3rd grade science. I understand the GE perfectly. Earth does not have to have the atmosphere of Venus or Mars (95% carbon dioxide) to warm from a GE. Earth's climate has shifted whether you chose to acknowlodge it or not. It currently kills 300,000 people every year.

http://www.nytime...ate.html

Jun 23, 2009
Water vapor IS a greenhouse gas, Is is the one that keeps us alive. It is not harmful like Co2 because it dissipates very quickly. C02 take DECADES!!!

So the 300,000 should not be an issue because AIDS kills more? So is 300K just below the minimum then? Is that how we should deal with things like H1N1 and any future disease? Ignore it till it kills at least half a mill? Who was your science professor? A cartoon character?

Jun 25, 2009
I hvae prove that AGW does kill 300K per year yet you think it does not. The study that came up with that number was very lengthy. You obviously didn't take the time to read it. And 300K is today's numbers. The number will get higher as we continue to pump out more Co2 and warm the Earth even more.

You need to go back to school and learn the difference between Co2 and water.

Jul 03, 2009
So how come all that water has not melted this much Antarctic ice in 1.5 million years? Because water vapor can't do that.

Jul 21, 2009
Precession is the Earth's slow wobble as it spins on axis. This wobbling of the Earth on its axis can be likened to a top running down, and beginning to wobble back and forth on its axis. The precession of Earth wobbles from pointing at Polaris (North Star) to pointing at the star Vega.


You forgot to mention Alpha Draconis, which was the last star at which the north pole pointed before it pointed to Polaris.

Jul 21, 2009
So how come all that water has not melted this much Antarctic ice in 1.5 million years? Because water vapor can't do that.


You are kidding, right??? I do not know of any ice cores going back that far. In addition, just 120,000 years ago sea level was at least 6 meters higher than at present. Just how do you think that happened, especially considering that CO2 levels were lower at that time than at present?

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