Last summer my wife and I went down to southern Ohio for a few days to, among other things, poke around for fossils. Southern Ohio has a large number of exposures of fossil-bearing sedimentary rocks spanning almost 200 million years in time. Exposures progress from the roughly 450-million-year-old Ordovician deposits around Cincinnati to the roughly 250-million-year-old Permian deposits near West Virginia.
On this warm, sunny August morning we were stopped at an outcrop south of Logan, Ohio, and I was digging around in some Pennsylvanian shale around 300 million years old. I was hoping to find something more interesting than the usual bryozoan, brachiopod, or cnidarian. Although the odds were weak, I was hoping to stumble across a small fish or amphibian. The shallow aquatic environment responsible for shale formation combined with the geologic time period made such a discovery possible, but the relatively rarity of fossils, especially those of vertebrates, made a find very unlikely.
My wife happened to snap this picture right before something noteworthy happened. I crouched down to remove some large shale flagstones. One by one I picked them up, turned them over, splitting the occasional piece along a bedding plane hoping to find a fossil encased inside. After a few minutes I picked up one large piece, and as I lifted it I froze for a moment. Warming itself under the rock was what appeared to be a young massasauga rattlesnake (Sistrurus catenatus, Viperidae) . It stirred from the disturbance and I slowly backed away, setting the slab of shale down only after I was at a comfortable distance.
Although the snake was likely cold and slow in the early morning, I wasn’t taking any chances. These poisonous snakes exist in my area in southeast Michigan, but they’re uncommon and I have no experience with them. I once owned a ball python (Python regius, Pythonidae), a constrictor with no venom. I found even that to be uncomfortable. I get a bit nervous around animals that can suddenly and without warning strike out at you.
In the future I’m going to be more cautious about digging around in loose rocks, and I’m going to make sure I have my camera with me at all times. I would have loved a picture of this snake for positive identification.