Mystery fossil! i have noidea for as to what this is. Any help is much appreciated. To me, it looks like it might be an ancient nataloid shell, or maybe a conulariid? It is from the decorah shale deposit in southeastern Minnesota. Any clues?


I apologize for the poor picture quality. Phones can only do so much.

I have enlarged the picture as to maybe add more detail when viewing.

An enrolled unknown species of trilobite

Does anyone know what species of trilobite this is? It is from Decorah shale, and is roughly 438 million years old. It was found in southeastern Minnesota. Any ideas?

The trilobite is shown here in the forefront of the image.

(center) This is a pygidium (tail) of a trilobite from southeastern Minnesota. (bottom right) A piece of a possible brachiopod shell on top of a crinoid stem piece. The entire stone is filled with brachiopods and other fossils, but many are hard to see in pictures.

Hello, my name is Sam. I am a Minnesota native, and I love the geology of my home state. I will probably post mostly about the fossils and wildlife here, but occasionally I'll post other things. I hope you will enjoy my blog, and if not, message me on how I can make it better.