January 31, 2011

Fossils: A Cheat Sheet

Fossils are pieces of the prehistoric puzzle, helping paleontologists put together the stories of the past.  These pieces of the puzzle can be, well, puzzling. This fossil cheat sheet* will answer the questions: What are fossils?  Where are they found?  What types of fossils can you find?

A fossil is any remain, trace, or imprint of a once-living animal, plant, or single-celled organism that has been preserved in rock.

Hard parts of an organism like teeth, leaves, pollens and bones are more likely to be found as fossils.  Soft parts and soluble materials tend to decay but can show up in the fossil record as molds or carbon film. Our friend the jellyfish is less likely to become a fossil for this reason.

Organisms that have slowly evolved over time are also more likely to be found as fossils.  Sometimes paleontologists can trace the evolution of an organism through the fossil record, too!

Species evolved slowly = greater chance of finding fossils

Organisms that evolved quickly had less time on earth.  The result?  Lower chances of becoming fossils. 

Species evolved quickly = less likely to find fossils
So what environments tend to house fossils? Places where deposition, or the laying down of sediment, has occurred.

Important fossil discoveries have been found in Washington State, including a 12,000 year old giant sloth that was found at SeaTac Airport.  The oldest known fossilized baleen whale (approximately 28 million years old!) was discovered in the state as well.
Want to see these finds for yourself? Come to the Burke Museum and check them out in the exhibit
Life and Times of Washington State!
Posted by: Andrea Barber

*The Burke is not responsible for test scores resulting from studying this blog for fossil tests or the literal use of these drawings (let's face it, the writer's artistic abilities are limited).