The Farthest North Fossils
Ellesmere and Axel Heiberg Islands in the Canadian Arctic are the northernmost part of North America, reaching to within 500 miles of the North Pole.
A recent article by Michael Lemonick in Time magazine reported on the discovery of the remains of an ancient forest on Axel Heiberg Island. The trees had once grown 150 feet tall and lived for as long as 1,000 years (they were so well preserved that the growth rings could be counted). One astonishing thing about the stumps is that they are 45 million years old! A second is that they are not petrified (that is, turned to rock with minerals replacing the cellular wood structure), but are mummified and can actually be burned. This could be explained by rapid burial and deprivation of oxygen, but the biggest riddle of all is how they could have grown there in the first place.
That far north of the Arctic Circle, the trees would have had to survive 5 months of the year without sunshine (necessary for photosynthesis), yet the trees resemble the remains of a redwood forest in Northern California. The best bet seems to be that they just turned off all the switches when the sun went down for the winter, and stood dormant until the next frantic growing season.
These trees are not the first evidence that the earth once had a much more moderate and uniform temperature. On Ellesmere Island (just east of Axel Heiberg Island where the trees were found), Malcolm McKenna of the American Museum of Natural History reports of the findings of vertebrate fossils ranging from "pre-crocodiles" to "pre-apes" (not his terminology), dating back to about 50 million years.
Within Alaska, there have been recently confirmed fossil finds of hadrosaurs, or duckbilled dinosaurs, north of Kotzebue. These animals lived about 65 million years ago, near the end of the Cretaceous Period--the heyday of the dinosaurs. At the end of the Cretaceous the dinosaurs and thousands of other species disappeared for reasons that are unknown to this day.
Out of all this, the primary question still arises: even if the global climate was far warmer then, how could these animals and the plants on which they depended for survival have lived in an environment where it's dark half of the year? Continental drift, putting the lands in which the fossils lay closer to the sunny equator, doesn't seem to work--at least not for the High Arctic islands. Of all the land masses on earth, they seem to have been among those that have shifted the least. Could it have been a tilting of the rotational axis of the earth, bringing more sunlight to what is now the Arctic? There is no known mechanism to account for that. As Archimedes is reported to have said, "Give me a lever long enough and a place to stand, and I can move the earth." But there was no place for a hypothetical Archimedes to have stood--no place for him to brace his foot.
What we may need to do is simply brace our minds instead, and envision an ancient world where the far north was comparatively warm, thickly forested, and inhabited by night-stalking dinosaurs among many other creatures. How this combination could exist is just one of the many puzzles that beg for a scientific answer.
