I found this guy in a small mudrock that I collected yesterday.
From what I understand, this is a common trilobite found throughout North America.
I found this a while back, different spot.
This I found in yet a different spot!
We find primarily parts of trilobites because of the molting process.
Here is a link to an excellent trilobite site and explanation of the molting.
Sam Gon’s site is also on the sidebar.
Note the time line of life for the Flexicalymene trilobite.
These last two I also found on the Google Advanced Image search function
and appear to be from the same site,
but I couldn’t seem to get back to that site to credit the author. 🙂