This is the “Fossil Friday” post #343. 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 in a very nice Pecopteris serpillifolia (see Mazon Monday #144) into our Mazon Creek Fossil Day in October 2026. P. serpillifolia is one of the rare varieties of Mazon Creek true ferns. It was described by Leo Lesquereux in 1879-1880.

There has been a bit of controversy around P. serpillifolia as some of Lesquereux specimens, including the holotype, are no longer considered P. serpillifolia.

This is a very nice, large specimen. Hunter did a bit of work to piece it back together. It was collected in the area of Pit 1. Thanks for sharing, Hunter!