A Petoskey stone is a coral colony that lived 350 million years ago when Michigan was a warm sea over the equator, during the Devonian time period. The coral is called Hexagonaria percarinata, meaning it has six sides. The individual corallites are skeletal cups with a mouth of soft tissue, which is represented by the darker areas on the fossil. These are easier to view with a little water poured on them. The surrounding hexagonal area was were the tentacles used to gather food such as plankton. Each cell of the corallite now is composed of silica, calcite and other minerals.
To log your find, please E-mail via profile the answers to the following questions:
1) During which geological period were Petoskey Stones formed?
2) On this boulder you will also notice there is more than one coral colony. How many coral colonies can you find on the top and sides of this boulder?
To learn more about Sleeping Bear Dunes National Lakeshore visit the link, http://www.nps.gov/slbe
This cache was created with help from participants of Michigan Teaching Excellence Program (MITEP) through Michigan Technological University