Foerstephyllum Colonial Coral

Here is an extinct colonial coral from the Ordovician period (approximate 440-500 million years ago). It is probably of the genus Foerstephyllum sp. and was found in the Liberty formation. Geographically that is eastern Jefferson County, Kentucky.

It reminds me of a wasp nest or bee honeycomb. I read that the vertical lines showing the stacked cells sort of work like tree rings. The wider the gap between the next wall the more plentiful food was and the narrower meant lean times.

You can see more images of this type of coral here and here.

A Fossil Mystery

I am trying to figure out if these are coral pieces or bryozoans.

REVISED (06/2008): It appears these are pieces of a branching coral described by Carl Ludwig Rominger (aka Charles Louis Rominger) as Dendropora alternans in 1876 (p.64, Plate 24, Figure 1) in his book Geological Survey of Michigan Lower Peninsula 1873-1876 Volume III Part II Palaeontology - Corals.
It is known today as Thamnoptychia alternans and described like that by E.C. Stumm in 1950.

Still some of the pieces I have are grooved with an almost fingerprint like pattern so maybe that is weathering but I have not found an image yet that looks like it. After looking at CORALS OF THE DEVONIAN TRAVERSE GROUP OF MICHIGAN PART V, TRACHYPORA
BY ERWIN C. STUMM and ALLEN S. HUNT paper and reading the description of this coral it seems that outer texture pattern might not matter in classification. Of course, I might be interpreting the academic speak wrong in this paper as well.

I continue to revise this entry but now after looking at Kentucky fossil corals, a monograph of the fossil corals of the Silurian and Devonian rocks of Kentucky, Pt. 2: Kentucky Geological Survey, xiii p., 139 pls. It appears to that surface pattern is on Plate 65, Figure 10 called Dendropora osculata or today called Trachypora osculata (Stumm). See this http://www.uky.edu/OtherOrgs/KPS/fossilcorals/images/davispl065.jpg

Thamnoptychia alternans Coral

Pieces of coral found in the yard. This fossil is pretty to find since it turns white 

This appears to be Thamnoptychia alternans branching coral described by geologist Carl Ludwig Rominger. It probably occurred in the Devonian period.