Polar in Australia?

As a meteorologist, Alfred Wegener was fascinated by questions such as: Why do coal deposits, occur in the icy ? And why are glacial deposits found in now tropical Africa? Wegener reasoned that such anomalies could be explained if these two present-day continents -- together with South America, India, and Australia -- originally were part of a supercontinent. This supercontinent extended from the to the South Pole and included a wide range of climatic and geologic environments. The break-up of Pangaea and its movement of the individual continents to their present positions formed the basis for Wegener's continental drift theory.

Recently, paleontologists (specialists in studies of fossils) have carefully studied some well-preserved remains unearthed at Dinosaur Cove, at the southeastern tip of mainland Australia. Dinosaurs found in most other parts of the world are believed to have lived in temperate (warm) or tropical regions, but these Australian , popularly called "polar" dinosaurs, seemed well adapted to cooler temperature conditions. They apparently had keen night vision and were warm-blooded, enabling them to forage for food during long winter nights, at freezing or sub-freezing temperatures.

Australian dinosaurs

The last of the dinosaurs became extinct during a period of sharp global cooling toward the end of the period (about 65 million ago). One current theory contends that the impact of one or more large comets or asteroids was responsible for the cooling trend that killed off the dinosaurs. Another theory for the cooling explains the sudden change and cooling was brought on by a series of huge volcanic eruptions over a short period of time ("volcanic winter"). The discovery of the polar dinosaurs clearly suggests that they survived the volcanic winter that apparently killed other dinosaur species. Why did they become extinct if they were well adapted to a cold climate? Paleontologists do not have the answers. However, this recent paleontologic evidence demonstrates that Australia has drifted north toward the equator during the past 100 million years. At the time when the Australian polar dinosaurs thrived, their habitat was much farther south, well within the Antarctic Circle.

In 1991, paleontologists discovered the Cryolophosaurus ellioti, a previously unknown dinosaur species and the only one found on the continent of Antarctica. Cryolophosaurus fossils were found at , located only 600 km from the present-day South Pole. This newly discovered carnivorous dinosaur probably was similar in appearance to the (see artwork above), except for a distinctive bony crest on its head. Studies show that the Cryolophosaurus lived about 200 millions years ago, when Antarctica was still part of a supercontinent and had a climate similar to that of Pacific Northwest--mild enough to support large plant-eating life, upon which the Cryolophosaurus preyed. With the break-up of the supercontinent, Allosaurus and Cryolophosaurus parted company, as Australia drifted northward toward the equator and Antarctica drifted southward to the South Pole.

Had the Australian polar dinosaurs and the Cryolophosaurus been discovered while he was alive, Alfred Wegener would have been delighted!

Dinosaur Cove