“Fossils occur in many forms.  The footprint or burrow of an animal preserved in rock is a fossil; a clam shell preserved in rock is a fossil; the imprint of a leaf on a rock is a fossil. A fossil is any naturally formed record of animal or plant life found in rocks that gives an idea of the appearance of the original organism.” — General Geology Report 40, Fossil Collecting in Pennsylvania, by Donald M. Hoskins, Jon D. Inners, and John A. Harper.

Excerpts from General Geology Report 40, Fossil Collecting in Pennsylvania (out of print).

Introduction, Pages 1-14, (1.40 MB)

Characteristics of the Major Fossil Groups

  • Pages 14-33 (1.72 MB) Includes sections on Protozoa, Porifera, Coelenterata, and Bryozoa.
  • Pages 34-49 (2.56 MB) Includes sections on Brachiopoda, Mollusca, Annelida, Arthropoda, Echinodermata, Hemichordata, Chordata, and plants.

Fossil plates

More Information

For more information on fossils in Pennsylvania, see Educational Series 2 Common Fossils of Pennsylvania. Also, read about Pennsylvania's state fossil, a trilobite known as Phacops rana.

T-rex at the Pittsburgh Office of the Pennsylvania Geological Survey

As a result of a generous donation, a cast of a Tyrannosaurus rex skull now welcomes visitors to the Pittsburgh office of the Survey. Although dinosaur tracks have been found in Pennsylvania, fossil delights in the state go far beyond dinosaurs. For example, see the next article below.

News about Swatara Gap

A few localities still exist where fossils can be collected freely and safely, such as the borrow pit in Swatara State Park. On August 5, 2004, PennDOT, in cooperation with the Pennsylvania Geological Survey, moved more than 200 cubic yards of rock from Swatara Gap to Swatara State Park. However, it didn't take long for those rocks to be history, too. More details are provided on the fossils left at the site.

Efforts will be made to find similar sites, including other areas near Swatara Gap. For now, our recommendation is to consider clubs and groups that organize official field trips to collect rocks, minerals, or fossils in Pennsylvania. Penn Minerals provides a list of such organizations.