This summer, Ted Daeschler found himself stuck in a pup tent as howling winds blew snow across the tundra. His only bunk mate was a shotgun to ward off polar bears.
Back home in Philadelphia, it was sweltering in the 90s.
Daeschler, the curator for paleontology at the Academy of Natural Sciences, had journeyed to Melville Island, some 450 miles above the Arctic Circle, in search of fossils.
"We were there for summer, but summer in the Arctic only lasts two weeks," Daeschler explained.
Even with the bad weather, his expedition was able to find what it was looking for - a variety of prehistoric fish.
They uncovered bits and pieces of armor-plated "placoderms," some resembling swimming hamburgers, others 10-foot-long predators.
There also were ray-finned fish, ancestors of trout and salmon, and - most important - fossils of lobe-fin fish, precursors of the first land animals.
The expedition - set up by the academy and the University of Pennsylvania - traipsed across Arctic islands for nearly five, snow-whipped weeks.
"We lost just about one out of every two days to bad weather," said Neil Schubin, co-leader of the group and a biology professor at Penn.
Daeschler and Schubin had come to the Arctic in search of 380 million-year-old fossils from the Devonian Period.
The Devonian is the geologic moment when animals with backbones left the oceans and, as Schubin put it, "invaded the land."
The expedition was most interested in finding fish whose fins were starting to turn into limbs. Daeschler called it "the fishy side of the transition."
The key to this transition is the lobe-fin fish. That class of fish, Schubin said, shares "a lot of characteristics with humans. . . . Their heads even look a little like ours."
Schubin had already done research on a number of lobe-fin fish fins that seemed to be turning into fingers and toes.
"But all we had was fins. We need whole bodies; that's why we went to the Arctic."
At the same time, the six-man team was aiming to document as much of the period's flora and fauna as possible. "We wanted to try to give a picture of the entire Devonian ecosystem," Daeschler explained.
The reason the researchers - who included Penn graduate student Marcus Davis and three Harvard University paleontologists - picked these islands north of the Barrow Strait was because they had just the right kind of rocks.
