Archean Polished Butterstone

This rock was found in southern Africa's Greenstone Belt.  The color of the rock definitely matches the formation name.  What is special about this rock called butterstone dated to the geologic eon Archean.  Thus the material is thought to be over 2.5 billion years old.

Bacteria and algae appeared at this time in the water.  Volcanic activity produced increased atmospheric pressure and temperature.  The higher temperature caused serpentization of the sediments thus the green color. In between the layers the micro stromatolites (like algal mats).

This fossil is for sale on eBay: CLICK HERE and another is for sale (ending October 11, 2011): CLICK HERE

Archimedes swallovanus Bryozoan

Archimedes swallovanus bryozoan found in Calbert County, Alabama.  Creatures existed in the upper Mississippian Period.

Thanks to Dave M. for the fossils.

Michela trabeatoides

The gastropod Michela trabeatoides lived in the Eocene.  Specimen found in the Stone City Formation (aka Whiskey Bridge) of Brazos River, near Bryan, Texas.

Thanks to Dave M. for the specimens.