Thursday, February 24, 2011

Phacops Rana from the Silica Shale

While exploring the eroded dumps of Silica Shale at Sylvania I happened upon the largest Phacops trilobite fossils I've ever found.

Here is an enrolled specimen, about the diameter of a silver dollar, with pyrite crystals forming on the eye lenses.

It's not a perfect specimen as some of the glabella (the part of the cephalon of a Trilobite that is between the eyes at the very front of the head) is missing.

I find it interesting that the pygidium of this animal looks like it's missing at first glance. But you can see that it's just separated and rotated inside the rest of the shell.

Here is another specimen that is enrolled. Not in as good a shape as the previous fossil but all the bits are there.

Finally there is this prone specimen that is also not in the best condition as the glabella and the left half of the cephalon is entirely missing. The fossil is about three inches long and is the largest Phacops fossil I've ever found.

1 comment:

  1. Those trilobites are all nice finds.

    Did you take any measurements on any of those fossils?

    Once the second Phacops shown in your post is cleaned it might be the best one intact in terms of visible surface area.