Wednesday, September 20, 2006
From Scientific American 'Ask the Experts':
What are the odds of a dead dinosaur becoming fossilized? - Paleontologist Gregory M. Erickson (homepage) of Florida State University (FSU) explains.
It is often stated in the paleontological literature that the chance an animal will become fossilized is 'one in a million.' This number is meant to be taken figuratively, the point being that the odds of surviving the rigors of deep time are extremely remote. Nevertheless, all field paleontologists know that the earth is biased when it comes to giving up its dead--the odds of an animal being preserved and consequently exhumed are much greater in some settings than others.
Studies by taphonomists (paleontologists who study the transition of animals from the biosphere to the lithosphere; taphonomy literally means 'burial laws') have shown that organisms that die on land in lush jungle locales are rarely fossilized. In these settings, there is little chance of being buried, scavenging vertebrates and insects are prevalent, bacteria that break down flesh and bones are abundant, and the soils are extremely acidic and tend to dissolve bones. As a result, remains of dinosaurs from such former surroundings are practically nonexistent. Conversely, dinosaurs are commonly found in areas that were once fluvial settings and in regions of extreme aridity. [Paleontology, Evolution, Palaeontology]
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