Acrocyathus Mississippian Fossil Coral

These rugose coral fossils were found in Floyd County, Indiana in the St. Louis Limestone.  This limestone dates back to the Middle Mississippian (Carboniferous) period.  The corals appear to be Acrocyathus floriformis? also referred to as Lithostronchia or Lithostrotion or Lithostrotionella. These coral fossils also are found in Kentucky, Missouri, West Virginia, and maybe Alabama. Thanks to Alan for help with identification.

See a Lithostronchia specimen on the KYANA Geological Society web site: CLICK HERE

UPDATE (2019-06-15): website link below has changed to this: http://www.uky.edu/KGS/fossils/fossil-coral-rugose-corals-mound-shape.php

Learn more at the Kentucky Geological Survey web site: http://www.uky.edu/KGS/fossils/rugosecolonial3.htm

See other Lithostrotion corals on Plates XXXVI and XXXVII: CLICK HERE

Cirroceras nebrascense Ammonite

The Cirroceras nebrascense ammonite fossil displayed at the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania (July 2011). This fossil was probably found in South Dakota.  The creature swam the Western Interior seas of the Upper Cretaceous (Mesozoic Era).  Its Carnegie museum accession number is CM 29908.

Visit the Carnegie museum web site:  http://www.carnegiemnh.org/

View another specimen at the U.S. National Museum of Natural History: CLICK HERE

Placenticeras whitfieldi Ammonite

The Placenticeras whitfieldi ammonite fossil displayed at the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania (July 2011). This fossil was found in the Black Hills of South Dakota.  The creature swam the Western Interior seas of the Upper Cretaceous (Mesozoic Era).  Its Carnegie museum accession number is CM 29833.

Visit the Carnegie museum web site:  http://www.carnegiemnh.org/