Last week we looked at a fossil that seemed to be swimming through rock. This week we see it from a different perspective:
As you might have guessed, this organism is small: maybe six centimeters on a good day. I liked the lines of this specimen; they seemed to hold so much movement. But, as is often the case, appearances can be misleading. This organism is an example of the genus Pentremites (species unknown). What you might guess to be a swimming tail is in fact a stalk. Like many modern sea lilies, the Pentremites were immobile stalked echinoderms. They were common around 330 million years ago, in the Carboniferous period.
When I saw this fossil’s tag, the location made me curious. I’ve been right at the intersection of 146 and 57 in Illinois. It’s pretty far down in the southern end of the state; a beautiful area, but not one many people visit. When I traveled there, I had no idea the area had rich fossil deposits. Interesting to think of how much there is in the world that we don’t see.
The winner this week? Dan Coleman! Congratulations, and thanks for playing! If you have a fossil you want to share, send your pictures to me at schoerning at ncse.com. And if you need another fossil fix, check out the UIowa Palentology Repository, who we thank for this week's fossil!
