History
Early attempts to estimate the longevity of dinosaurs used allometric scaling principles. Ages were determined by dividing individual mass estimates by rates of growth for similar, extant taxa. For very large individuals, growth rates were extrapolated to dinosaur proportions using regression analysis. The results of these investigations have been extremely variable as they depend on mass estimates and growth rates that are highly at odds with one another.
For example, longevity estimates for the sauropod Hypselosaurus priscus range from a few decades to several hundred years. Recently, however, it has been shown that most dinosaur bones have growth lines that are visible in thin sectioned material viewed under a polarized light source.
Read more about this topic: Age Determination In Dinosaurs
Famous quotes containing the word history:
“It may be well to remember that the highest level of moral aspiration recorded in history was reached by a few ancient Jews—Micah, Isaiah, and the rest—who took no count whatever of what might not happen to them after death. It is not obvious to me why the same point should not by and by be reached by the Gentiles.”
—Thomas Henry Huxley (1825–95)
“Whenever we read the obscene stories, the voluptuous debaucheries, the cruel and torturous executions, the unrelenting vindictiveness, with which more than half the Bible is filled, it would be more consistent that we called it the word of a demon than the Word of God. It is a history of wickedness that has served to corrupt and brutalize mankind.”
—Thomas Paine (1737–1809)
“The awareness that health is dependent upon habits that we control makes us the first generation in history that to a large extent determines its own destiny.”
—Jimmy Carter (James Earl Carter, Jr.)