Hexagonaria percarinata
Sleeping Bear Sand Dunes National Shore Line, Michigan

This coral is called "Petoskey Stone" locally and is the state stone of the State of Michigan. It forms the bedrock in much of that and contiguous states and provides circumstantial evidence that 350 million years ago much of what is now the middle of our country was under the sea. Furthermore, it can be concluded from such luxuriant coral growth that the climate had to have been tropical.
Copyright © 2003 Giraud Foster & Norman Barker