July 19, 2002
When the Arctic was too
hot for muskoxen
Researchers travel to
Ellesmere Island in search of fossils from an era when the North was warm and
swampy
Dr. Jaelyn Eberle
in July 2000 in the Denver Basin in Colorado.
(PHOTO BY DAVID TAYLOR)
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A herd of thick-coated,
shaggy muskoxen graze on bits of vegetation poking up through the frozen earth
on central Ellesmere Island. Their small curved horns can be used to break through
the ice to get to the grasses. This animal, with its long hair and squat stature
is well adapted to the high Arctic, where it is dark for four months of the
year and the temperature can dip to -65 C.
Fifty-five million years
ago, a muskox in the same area would have had to shed many layers of hair to
be comfortable. At the time, what is called the Eocene period, the Arctic was
warm and swampy. Alligators, turtles and snakes slithered and crept on the same
ground now beset by permafrost.
This summer, a group of
scientists will be crawling over parts of southern Ellesmere Island looking
for fossilized bones of these warm-weather creatures.
Paleontologist Dr. Jaelyn
Eberle and three fellow researchers left last Wednesday for the two-and-a-half-week
expedition. They will travel to four parts of the island Stenkul, Baumann
and Sör Fiords, as well as the Swinnerton Peninsula.
Priscilla McKenna, left,
and Mary Dawson. Dawson, a true Arctic pioneer started prospecting for fossils
in the Arctic in the early 1970s.
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"The Arctic Eocene
55 million years ago was just a very different place," Eberle explains
in a phone interview from the Canadian Museum of Nature in Ottawa, where she
is an ancient mammal expert.
"I picture what I
see in the Arctic in the Eocene as very much like todays southeastern
United States including eastern Texas cypress swamps filled with alligators,
all sorts of turtles, these red-eared sliders sitting along the edge of the
bayou. This is the kind of environment I see a nice, wet, humid swamp."
This is the second summer
Eberle has done fieldwork on Ellesmere. Last year she was part of a fossil-hunting
expedition in the central part of the island.
"Last summer we got
more fossil mammals, including a lot of fossils of a guy called coryphodon,"
she says. Coryphodon was a hippo-like mammal, she explains. "Hes
probably kind of round and hung out in the swamps. Up in the Arctic, we get
mainly teeth and jaws, so you cant really say a lot about their bodies."
Teeth are the hardest part
in the body, she says, so if anythings going to fossilize theres
a good chance it will be a tooth. Jaws are also often well preserved in the
Arctic, probably because they contain teeth and because they are solid bones
especially in mammals.
A tooth from Lambdotherium,
a rhino-like animal, that lived in the Canadian high Arctic during early Eocene
time. The tooth was found near Bay Fiord in the summer of 2001.
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"We do get body parts,
like leg bones, or parts of them, but theyre not as well preserved and
can be difficult to link up with the head unless youve got something to
associate with it," she says. "As the permafrost does its thing, the
stuff gets churned up and broken up."
Scientists have found some
partial skulls, including one from a tapir, an animal now found living in South
America, as well as fossilized pieces of creatures related to todays flying
lemurs, and other rodent relatives that were most likely tree-climbers.
Yes, Eberle says, the Arctic
was forested 55 million years ago.
"Were dealing
with an environment that probably didnt dip below freezing very often
if at all." That means there was no ice. "We find trees. Ive
actually got pictures of [fossilized] trees up there."
Scientists have also found
pieces of brontotheres, which are big rhino-like mammals that lived throughout
North America.
"We find chunks of
their teeth up North, which is kind of cool," she says. "These are
big guys, too, and would have been walking around munching on plants."
But aside from the fun
of finding these ancient treasures on the surface of the Eureka Sound Group
rocks, research on this period is important to understanding todays environment.
The 55-million-year-old
Eureka Sound Group rocks near Bay Fiord on central Ellesmere Island.
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"What we can say is
55 million years ago was about the warmest time. It would have been the height
of climate warming in the last 65 millions years," she says. "Today,
with our overall concern of global warming, I think its really neat to
start looking at past global warming events, including this one, which was the
height of it, just to get an idea of what goes on and what sort of organisms
occur where."
Warm-weather animals lived
in the Arctic but still survived on minimal amounts of light, Eberle says. Researchers
are looking at these animals descendants to see if there is anything in
their biology or physiology that might allow them to flourish in a dark, warm
world.
Eberle says scientists
have learned that a lot of animals appear rather suddenly in North America at
the very beginning of the Eocene era. Some scientists suggest these animals
may have come out of Asia, possibly through the Arctic, across the Bering Strait,
and over some sort of land bridge.
Malcolm McKenna prospects
for fossils in Eureka Sound Group rocks near Bay Fiord during a research expedition
last summer. The central-Ellesmere Island site turned up fossils from ancient
mammals.
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"The Arctic to me
is a very important bridge between mid-latitude North America and both Asia
and Europe," she says.
Eberles expedition
received US$23,250 in funding from the National Geographic Society Committee
for Research and Exploration, and will get logistics support from the Polar
Continental Shelf Project of Natural Resources Canada.
Two pioneers of fossil
research on the Arctic, Dr. Mary Dawson of the Carnegie Museum of Natural History,
and Dr. Howard Hutchison of the University of California at Berkley, will join
Eberle in the field. University of Calgary geology professor Dr. Cindy Reidiger
will also travel to Ellesmere with the team to study and date the rocks in which
the fossils are found.
Eberle says a final report
of their findings will be submitted to the government of Nunavut and the fossils,
although property of the territory, will go to the Museum of Nature for study.
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