Wednesday 10 August 2011

Continuing The Theme Of Australian Polar Dinosaurs

An example of bone growth rings
from the dinosaur  Hypacrosaurus
New studies of dinosaur bones found in Australia suggest that polar dinosaurs did not hibernate. A previous study suggested otherwise, making polar dinosaurs rather different to their temperate and equatorial cousins. If you cut a fully bone of any creature in half, you would find a series of growth rings similar to those of a tree, documenting the growth stages through its young life. In temperate and equatorial creatures, these rings are fairly consistent in size and density.

In polar creatures, these rings vary from an average size and density to a reduced version. This reduced version appears in the winter months when the metabolic rate is reduced and growth slows down. Scientists expected a similar pattern to occur in polar dinosaurs. The new study, however, shows that such a pattern is absent. The study was conducted by a graduate student at the Montana State University by the name of Holly Woodward. Woodward believes that the results could shed some light on why the dinosaurs were so successful for 160 million years.

She stated 'this tells us something very interesting; that basically from the very start, early dinosaurs, or even the ancestors of dinosaurs, evolved a physiology that allowed an entire group of animals to successfully exploit a multitude of environmental conditions for millions of years. Woodward went on to say 'if we were trying to find evidence of dinosaurs doing something much different physiologically, we would expect it to be found in dinosaurs from an extreme environment such as the South Pole, but based on bone tissues, dinosaurs living within the Antarctic Circle were physiologically similar to dinosaurs living everywhere else.'