This is the “Fossil Friday” post #305.  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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Taking a little break from Mazon Creek fossils this week with a beautiful, complete Receptaculites, sp. (Fisherites) from Northern Illinois. In Illinois, Receptaculites are rarely found complete. This one appears to be very nicely preserved. It was sent in by Gregg Weiner, who found it in a creek near his house.

Their phylogenetic origin has long been enigmatic. Originally believed to be sponges, they have also been called sunflower corals. Currently they are considered calcareous algae, probably of the order Dasycladales. With their fossils found on all continents except Antarctica, they enjoyed a wide-spread distribution from the Ordovician to the Permian.

Thanks for sharing, Gregg!