|Lycopsid tree root or Stigmaria ("root")|
Basically, we were walking around a pretty area and I saw some rocks that looked like tree stumps with the bark ripped off. With a closer look, it was pretty obvious that these were plant fossils. I looked them up (thanks, google) and according to the internets these were Lycopsid tree roots and are abundantly found in coal deposits (we were near a strip pit so it's appropriate that we would find these).
Now...here's the wikipedia link. http://en.wikipedia.org/wiki/Lycopodiophyta
Fossils, man. So old. I sound intelligent today.