This is the "Fossil Friday" post #163. 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!
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We have another Mazon Creek fossil today. There are a few species of shark egg cases known from Mazon Creek. Palaeoxyris prendelli is the most common species. P. prendelli was described by Leo Lesquereux in 1870 from fossils found in Lancashire, England. Lesquereux was a Swiss born bryologist and a pioneer in American paleobotany. For a long time, these fossils were thought to be plant parts. For more information, see the Field Museum guide written by Jack Wittry.
Here's what Wikipedia has to say about Palaeoxyris.
Palaeoxyris is the prehistoric shark egg capsule morphotype of the family Hybodontidae with a predominant occurrence in ancient freshwater environments. They comprise a beak, a body and a pedicle, with the beak merging into the body. They display a conspicuous right-handed spiral of ridges around the body, and in some cases, the pedicle.[1] Originally described as plant remains and controversially discussed within the floral kingdom it took decades before their true nature as animal eggs was revealed.[2]
This particular specimen was collected from Pit 3 during the summer of 2022. It was in the freeze/thaw process for about 8 months. It opened about a week ago, so stay patient... good things may happen!
