This is the "Fossil Friday" post #66. 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!
-----------------------------------------------------
ESCONI Paleontology Study Leader John Cataloni sent us some Waldron echinoderms for last weeks Fossil Friday. For this week, he sent along some cephalopods from the Galena Formation, which dates to the Upper Ordovician Period. These specimens were collected in northern Illinois, but the Galena extends into Wisconsin and Iowa. Thanks for the contribution, John!
The Galena Formation consists of pure carbonates with some chert. It overlies (younger than) the Platteville Formation and straddles the Mohawkian Series and the Cincinnatian Series boundary. Since it was deposited after the Deicke K-bentonite outage, there is a limited faunal diversity but molluscs and Receptaculites oweni (“sunflower coral”) are usually available in the Wise Lake (AKA Stewartville). ESCONI takes field trips into quarries that expose Galena rocks. The specimens pictured were all collected from the Wise Lake Member, which is equivalent to Edenian rocks in the Cincinnatian area (Kope Formation), at a now abandoned and water-filled quarry in northern Illinois.
Ephippiorthoceras sp.
Lambeoceras confertum
Metaspyroceras sp.
Probillingsites sp. 1
Probillingsites sp. 2
Westonoceras sp.
