Stromatoporoids

In solidarity with my fellow bloggers at Views of the Mahantango and Swimming the Ordovician Seas, I present a post on local stromatoporoids.

Looking at some large pieces of Silurian Period Louisville Limestone that reside in the flower bed, revealed quite a bit of biodiversity.  A chunk of limestone appears to contain the partially eroded remains of a sponge.

Part of the rock contains Halysites coral which dates it to the Silurian Period.

A Silurian brachiopod with crinoid stem pieces with a Halysites coral in the background in another section of the rock.

This tube coral is somewhat of a mystery. It looks like a Devonian coral but since this rock has the Silurian Period index fossil Halysites this must be Louisville Limestone.

Close up of Silurian Period brachiopod shown earlier, that might be a Sphaerirhynchia.

These next two pictures are of a Silurian Period sponge fossil with a lot of layers.  It is almost 20 cm wide.  Fossil found in Jefferson County, Kentucky.

This next type of stromatoporoid is one of my favorites. It is a mounding sponge and the shapes sometimes remind me a scoop of chocolate ice cream.

Mounding Sponge Fossil

Louisville Limestone

Silurian Period - Jefferson County, Kentucky

The Falls of the Ohio State Park Visitor Interpretation Center has a nice display on these ancient sponge creatures.  Paraphrasing it, the Jeffersonville Limestone found at the park has about 30 identified species of calcium carbonate fossils.  The creatures typically are found in sheet, hemispherical or mound-like shapes.  Colonies could range from 30-250 cm in size.  It is thought these sponges existed in warm, clear, shallow seas.  The fossils might be related to modern sclerosponges.

Hindia sphaeroidalis Stromatoporid

Devonian Period

Jeffersonville Limestone - Louisville, Kentucky

Matting Sponge on Heliophyllum Coral

Devonian Period

Beechwood Limestone - Clark County, Indiana

Learn more about stromatoporoids at the Kentucky Geological Survey web page.

Unknown Ordovician Coral

Unknown coral found in the Grant Lake Limestone of Bullitt County, Kentucky.  It is from the Upper Ordovician Period (460-445 million years ago).

Billingsastraea yandelli Coral

Very neat coral called Billingsastraea yandelli from the Devonian Period.  It was found in the Jeffersonville Limestone of Jefferson County, Kentucky.

The holotype for this fossil is stored at The University of Michigan Museum of Paleontology which Erwin Stumm listed in 1964 as specimen #13877.  I checked and it has not been cataloged in their on-line database yet.

Thanks to my cousin for loaning it to me so it could be photographed.