Friday, May 16, 2014

A gastropod's lesson.

Guess what happens when you do an unusual project without taking before and after pictures? People might not believe your claims of having done the project.

What does this have anything to do with biology or the photo at right?

This fossil is a cast from a gastropod shell found in Ordovician-age rock found along the Mississippi river in the Twin-Cities of Minnesota. The local Ordovician-age rocks are chock full of brachiopods, but contain very few gastropods. In modern sandy ocean environments, there are very few brachiopods and gastropods are everywhere. The mix of species found within this particular ecosystem has changed dramatically over time, even though the environment is likely to be much the same now as it was back in the Ordovician.

When I found the fossil, only the broken off tip and edge of the outer whorl were evident. My new fossil-hunting-buddy didn't see these hints for what was buried within the rock and expressed skepticism when I pointed them out. My intuition, from fossil hunting periodically over the last decades, led me to be almost certain there was a snail hiding in the rock. Yesterday it was sunny and relatively warm, so I decided to go about excavating the gastropod from its tomb. I sat on the sidewalk at the back of my house and carefully chiseled away the uninteresting (to me) rock surrounding the fossil.

As is common for me, I didn't think to take a photo until the project was complete. You'll just have to (or not) believe my claim of having found and prepared this fossil myself.

When I collected this specimen, I noted another gastropod hiding in a rock which was too large for me to carry. I now have some better tools and I should be able to extract it from the boulder it calls home. If I do collect and prepare it, I'll make sure to take more photos of the process.


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