Fossil Laevicaardium laevigatum laevigatum bivalve shell both halves. This shell does have a crack as seen in pictures great for study.
Lenght: 2.90" / 73 mm
Width: 1.95" / 49 mm
Fort Thompson Formation, Charlotte County, Florida, USA
Scroll down for more pictures, put mouse over picture of fossil and zoom in the upper picture.