This is the “Fossil Friday” post #287.  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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Hunter Nettles brought an absolutely breathtaking specimen of Palaeoxyris multiplicatum to the Mazon Creek Fossil Day. This specimen was found last year (2024) in the Pit 1 locality of Mazon Creek.

Palaeoxyris multiplicatum is a species of shark egg case from the Mazon Creek fossil deposit. Jack Wittry wrote a very nice field guide of Palaeoxyris for the Field Museum.

Thanks for sharing this amazing specimen, Hunter!

Here is how Hunter found it. His boot is a good reference for size. It’s 7+ inches in length.

And, here it is after a gentle cleaning.