Guide for Beginning Fossil Hunters
Fossil GuideAdapted from ISGS Geoscience Education Series 15, 2002
by Charles Collinson
Long before the first humans appeared on Earth and such familiar features as our lakes and rivers were formed, the Earth was inhabited by plants and animals.
Even though humans are the only creatures able to record their history, we know that plants and animals lived an incredibly long time before human beings were here to see them. We have evidence that single-celled organisms swarmed in the seas half a billion years ago. We know that after this small beginning animals grew bigger, more complex, and more varied, and that after millions of years such monsters as dinosaurs evolved. We can also prove that they in turn gave way to the mammals that today dominate the Earth.
We know these things because the prehistoric creatures left behind the telltale marks that we call fossils. Some fossils are merely foot tracks or worm holes. Others are impressions of an entire animal or plant. Many are bones or shells—or even skin and hair.
The materials in which the fossils are encased were not always rocks. At one time they were mud or sand on the floor of a sea or sand dunes on an ancient land. As time went on, these sediments were buried under more sand and mud. Layer after layer piled up, and the sediments with their enclosed fossils were cemented into rock.
Pentremites, a blastoid
The great numbers of fossils in the rocks represent only a small part of all life that has existed on our planet. For every fossil we see, millions of animals have lived, died, and been destroyed without leaving a trace. Nevertheless, by carefully collecting the fossils and recording the layers of rocks they came from, we can reconstruct hundreds of generations that have lived on both land and sea at one time or another.
Paleontologists devote their lives to seeking and studying fossil remains in order to interpret Earth history, but the search for fossils can be an adventure for almost anyone. It can be an excursion to an ancient beach or a plunge to the bottom of a long-vanished sea.
A trip to a quarry may yield fossil clams and corals; a search through a strip mine may produce tropical ferns; mastodons or snails may be the subject of a hunt along the river bluffs. All such excursions provide good outdoor fun—whether for an afternoon, a weekend, or an entire vacation.
In addition to outdoor adventure, a successful hunt provides interesting trophies for your collections. Many of science's most valuable fossil finds have been brought in by amateur hunters.
Common Types of Illinois Fossils
Several people contributed to this project. Christina Cleburn, Joseph A. Devera, Wayne T. Frankie, Dennis R. Kolata, Rodney D. Norby, and George L.H. Stone are thanked for their loan of fossil specimens. The manuscript reviews of Dennis R. Kolata, Rodney D. Norby, and Wayne T. Frankie are appreciated. Illustrations were prepared by Margaret L. Whaley, Charles Collinson, and Marie E. Litterer. Pamella K. Carrillo created the cover design and layout. Production editor was Cheryl K. Nimz. Photographs were taken by Joel M. Dexter. The Web version of this publication was created by Sally L. Denhart.
Purchase the Book
The printed version of Guide for Beginning Fossil Hunters can be purchased from the Shop ISGS Web site. for $5.00 plus S&H.
Updated 09/23/2011 SLD