Monday, September 6, 2010

Silicified Crinoids

Here are some huge Crinoid stem sections from the Fort Payne formation at Lake Cumberland, KY. These stems which can get up to 3/4" (2cm) in diameter have been silicified (replaced with silicon oxide, or Quartz) and preserved in a hard limestone.

Here are a grouping of different sizes and species:

Most are tan to white colored but others have been preserved with a light grey-blue color.

The stem sections preserve details very well and there are many that display growth scars of the cirri which were like arms that grew off the sides of the stems to enable the animal to grasp parts of the reef and act like an anchor. These pieces show scars and also how the columnal was modified at the attachment point.

Some species of Crinoids had a more root like base similar to Ancyrocrinus

Due to their unusual shape and growth pattern, these segments could possibly be identified as the stem sections from an Eucladocrinus.

Here is a crinoid calax of the genera Eretmocrinus

Shells of spirifred brachiopods can be found as well mixed in with the crush of crinoid stem pieces.

Thanks to Mike from Louisville Fossils for the specimens. Click Here, Here or Here for more about these fossils and where they are from.

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