Natural Science Forum / Biology / Paleontology / January 2006

If you could photograph it when wet, it would be easier to see the detail
of the fossil structure.  It appears to be a tabulate coral (possibly a
Favistella species), possibly from the Bardstown reef member of the Drakes
formation (late Ordovician) in Kentucky, and has been found elsewhere in
the lower Silurian, but don't quote me on that because I can't see the
detail of the specimen all that clearly.  If my identification is correct,
this fossil is common in the Bardstown reef, and is known to occur often as
a hollowed out nodule with quartz, and sometimes calcite crystals inside,
and sometimes as a solid mass with crystals of quartz or calcite on the
outside as well.  Oftentimes, they are silicified with tiny quartz crystals
occurring within the theca of the corallites.  They can be rather large,
but your is about average for the genus.

Here is an example of a Favistella species from Kentucky:

http://www.uky.edu/KGS/coal/webfossl/pages/tabulatemound3.html

I hope this helps you.

George

A hunk of eroded coral is my guess.