Monday, June 29, 2009

Silurian Horn Coral - A Mystery Solved

Recently, I have been collecting Silurian corals. I found this one which has several interesting aspects. One it shows four horn corals that have budding out of the main one and another coral that has budded out of its base. Second, the smaller horn coral at the base has holdfasts coming out of it.

It is this second point that merits my study today. I have been finding small horn corals with marks on their horn exterior surface and sometimes I find "spines" intact (see green arrows on first picture). At least that is what I assumed till I found this specimen. My thought was they were spines that kept snails from moving up the horn wall (corallum?) to the calice or horn rim. They reminded me of spines on crinoid calyx. I have found what appear to be snail boring holes or track lines on the corallum on other horn corals, so it made sense.

This fossil shows one of them intact that it is holdfast to anchor the smaller horn to the larger horn. So these protrusions were used as anchor lines to bond the corals together in this case.

These pictures where taken quickly under an incandescent light and I was not using a tripod. I will post more about this fossil later since it shows a good example of the budding reproduction process used by horn corals.

Reading up, the book calls the Silurian period, the "Age of Corals". From what I can tell the official coral of that period should be the Halysites chain coral. The Fossils of Ohio book identifies the following phylum has Silurian: Amplexus, Cyathophyllum, Holophragma, Rhegmaphyllum, and Zaphrenthis.




3 comments:

Saili said...

Hmmm, that was interesting. Looks like somethings will always remain mystery.

I myself has been trying to solve the mystery of the legend that forces you to have "earn it before

having it", for a wile now. Could not understand much though.

Let me know in case you get to understand the mystery of the Old Hound and the Legend

By the way, good writing style. I'd love to read more on similar topics

Anonymous said...

I live in Richmond,Ky and have been collecting pieces of fossilized coral myself.I have found many interesting pieces and some look very similar to yours.I would love to know what this other stages or pieces are? Please email me.

Fossil Detective said...

I will post a recently found fossil that shows a larger colony of these attached together and showing new horns budding out of older horn corals. See the entry for July 31, 2009.

I would e-mail you but no e-mail address was left in your comment. You can e-mail me at: louisvillefossils@gmail.com

Good luck with your coral identifications.