This is the "Fossil Friday" post #194. Expect this to be a somewhat regular feature of the website. We will post any fossil pictures you send in to [email protected]. Please include a short description or story. Check the #FossilFriday Twitter hash tag for contributions from around the world!
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Today, we have a nice Asterophyllites equisetiformis from the Pennsylvanian deposits near Terre Haute, Indiana. The concretions is that area come from the Dugger Formation, which sits atop the Springfield coal member. The Dugger Formation is the uppermost formation in the Carbondale Group. The coal member of the Dugger Formation has been correlated with the Danville coal in Illinois and is now referred to by the same name. It's been dated to about 305.5 million years ago, a little younger than the Colchester coal of Mazon Creek. We did a post about the fossils of Terre Haute in Mazon Monday #36. The spoil piles to the south of Terre Haute in Fowler Park come from the Chieftain #20 mine, which closed in 1969. The plant and animal fossils found in this locality are very similar to what is found in the Mazon Creek area.
A. equisetiformis is related to Annularia, both are parts of the Calamites plant. Calamites is related to modern day horsetails. We looked at A. equisetiformis in Mazon Monday #103.
