Sunday, October 25, 2009

Use the Word "Never" Carefully

The Encyclopedia of Louisville Edited by John E. Kleber and published by The University of Kentucky in 2001 is a great resource for information about Louisville, Kentucky. This encyclopedia included 1,799 entries created by over 500 writers.

It has a number of nice entries that relate to geology and paleontology: Falls of the Ohio, Falls of the Ohio State Park, Fossils, Fossils at the Falls of the Ohio, Geology, Fauna, Jeptha Knob, Mineral Resources, Knobs, and Quarries. The previous subjects are a few I found in the book but I did not try to find every one.

The entry that is the attention of this post is the one entitled Fossils. This entry takes up more than two pages of the encyclopedia as it covers fossils found through out the different time periods exposed in the Louisville, Kentucky area. The paragraph on blastoids I found of particular interest. On page 314, it is stated: "Blastoids were similar to crinoids, with a more robust nut-shaped body. The delicate tentacles and stalk are never preserved."

Yikes! One cannot find a blastoid that still with its stalk (stem) or tentacles (brachioles)? While I have never found a blastoid with an attached stem though I have only been to 3 sites that have blastoids. It would seem to me the use of the word "never" should be applied with caution.

When I visited the Cincinnati Museum Collection Center, I opened one drawer and saw this specimen. It is a large plate with an intact Pentremites blastoid. The picture quality is poor but the lighting and no tripod made for less than ideal photography. The segments of the blastoid are labeled. I was amazed to see such a fossil and it was one of my favorites of those viewed that day.

Closer view of the top of the blastoid Pentremites.

As you can see the stalk and tentacles of this blastoid have been preserved. So the lesson, be very careful when using the word "never" because it can come back later and bite you!

Brachiopod Atrypa reticularis

This brachiopod is from Benton County, Tennessee. It existed in the Lower Devonian Period and was found in the Birdsong Formation. The brachiopod was called Atrypa reticularis.

Thanks to Herb for providing the specimen.

As a comparison, here is an Atrypa reticularis from the Middle Devonian Period found in Saharan Africa. The specimen is from the natural history museum in Paris, France.