Wednesday, December 1, 2010

Scientific American on Bryozoans

The Scientific American web site has posted an entry about bryozoans entitled, "Excuse me, Sir. There's a Moss-animal in my Lake" by Jennifer Frazer.   Great article describing a find of a fresh water bryozoan in the state of Virginia.  She later covers bryozoan anatomy and fossil history.  Like the line in the article, "Bryozoans are like the whales of the coral world".  Also nice reference link to the image of the Archimedes bryozoan!

Hederella bryozoan on Orthospirifer brachiopod
Devonian Period - Indiana

Branching bryozoan
Ordovician Period - Kentucky

Constellaria bryozoan
Ordovician Period - Kentucky

Dolatocrinus Crinoid Stem Piece

Finally, a crinoid stem that can be identified at least to the genus name!  This Middle Devonian Period crinoid fossil is a Dolatocrinus known by those flange pieces protruding off the stem.  There are quite a few species of Dolatocrinus as shown on this Falls of the Ohio State Park fossil web page

A small booklet entitled Middle Devonian Type Jeffersonville Limestone at the Falls of the Ohio by James E. Conkin, Barbara Conkin, and Larry Steinrock published in 1998 defines the stratigraphy of where this fossil can be found on page 9.  The figure on the page shows it to be from the upper part of the Jeffersonville Limestone (33+ feet thick) in the Paraspirifer acuminatus zone (17.5 feet).  It further narrows it to the Elaeacrinus verneuili (Römer [aka Roemer], 1851) zone.

Fossil was found in Jefferson County, Kentucky.