This is the “Fossil Friday” post #309. Expect this to be a regular feature of the website. We will post fossil pictures you send in to esconi.info@gmail.com. Please include a short description or story. Check the #FossilFriday Bluesky/Twitter hash tag for contributions from around the world!

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Today, we have a cute little Acanthotelson stimpsoni (see Mazon Monday #52) from the Mazon River. Acanthotelson stimpsoni is a syncarid shrimp. It’s the most common shrimp found in the Braidwood fauna.

A. stimpsoni was described in 1865 by F.B. Meek and A. H. Worthen.  Fielding Bradford Meek and Amos Henry Worthen were both prolific namers of taxa back in the middle 1880’s.  They collaborated on many papers through the years. Meek worked at the USGS.  A.H Worthen was the second state geologist of Illinois and the first curator of the Illinois State Museum.  He has an extensive fossil collection, which now resides at the Prairie Research Institute PRI at the University of Illinois.  Acanthotelson was named for another early contributor to American science – William Stimpson. Stimpson worked at the Smithsonian Institution and was later the director of the Chicago Academy of Sciences.

This little treasure comes from Linda Harden, who collected with a group of us on Pit 11’s opening day this year. We got to talking about concretions from the Mazon River and how they tended to break open. Sometimes, you get raised areas within the layers can contain fossils, other times… nothing. We were discussing whether the empty raised areas were failed fossils. They could be.

Thanks for sharing this little treasure, Linda!