This is the "Fossil Friday" post #140. 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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What says Christmas more than a fossilized shark egg case from Mazon Creek? Well, Palaeoxyris has always reminded me of the finial Christmas ornaments.
A particularly large species of Palaeoxyris is P. multiplicatum. Here is a description from the Field Museum's Palaeoxyris field guide. That guide was created by renowned Mazon Creek author and ESCONI member Jack Wittry.
Palaeoxyris multiplicatum: Unlike other species of egg cases, the outer egg cover is rigid. When compressed it shatters into broken elongated fragments. There are no known complete examples of the band pattern. Other than the shattered apparence it has two features that help separate it from the other egg cases. The sutures abruptly change angle as they enter the body from the beak. And they are nearly straight as they run down the pedicle. Rare.
I visited Jack and the museum back in mid-December and took a few pictures of some rather large specimens.
This specimen was found by Andy Hay and donated to the Field Museum by past ESCONI President Jim Fairchild.
A quite large and detailed specimen from the Field Museum collection.
