Investigation of the Polar Dinosaur
Today we know through the evidence of fossils that dinosaur and other large reptiles once lived on every continent on earth. If you were a paleontologist in charge of finding fossils where would you look first? In the search for evidence the icy continent of Antarctica would be perhaps the last continent you would think to search. However, during the last twenty years a remarkable number of prehistoric fossils have been found in regions close to the South Pole. Beginning in 1960 with an expedition lead by a man named Spitzbergen, fossilized footprints from non-avian dinosaur showed the region once had a drastically different climate. In the years that followed more fossilized remains were collected in costly expeditions, often to remote areas near the north and South Pole. However, each find can present unique information about physiological adaptations various forms of life made to polar latitude temperatures during the Mesozoic era. An article “Polar Dinosaurs” by Thomas H. Rich in Science, published in February of 2002, explores the fossil evidence and presents the following ideas about the environment and the types of creatures who lived and adapted to the seasonal conditions present at these polar latitudes.
The ice fields of the North Slope of Alaska we know today are thought to have had temperatures ranging from 13-2 degrees Celsius during the Cretaceous period. This hypothesis is based on evidence from flowering plants, and leaf fossils found from the late Cretaceous found in the region. So life around the poles existed in a climate similar to that of Portland, Oregon, which has a mean temperature of 12 degrees, and may have gotten as cold as Alberta Canada’s average of 4 degrees. Fossil evidence found near the northern polar latitudes shows the dinosaurs that lived there to be similar to their southern relatives. However, a lack of evidence in certain species, especially crocodilians (cold blooded reptiles), would seem to suggest some non-avian dinosaurs were warm blooded and able to survive near freezing temperatures.
In southeastern Australia, temperatures during the Mesozoic were thought to be even lower than in the North. Deposits of dinosaur fossils along with hummocky vegetation and the presence of permafrost suggest the creatures lived in temperatures between 3 and negative 6 degrees Celsius. The size and amount of some of the vegetation is unexplainably large serving in temperatures unheard of for vegetation today. Dr. Rich writes, “It is difficult to imagine how this community functioned if temperatures were as low as physical indicators suggest. “
Did the earth rotate on a different inclination during the Mesozoic era? It would explain the high temperatures and actually give regions in high latitude longer periods of daylight. It is not certain if the...