This is the "Fossil Friday" post #221. 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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Artist's reconstruction of the extinct Holocephalian Edestus heinrichi
Another contribution to Shark Week.... an Edestus heinrichi shark fossil jaw with a tooth. Edestus sharks are known from the Pennsylvanian Period. The genus was established by Joseph Leidy in 1856, when he described Edestus vorax. Edestus is one of the sharks known for its strange tooth whorl, which consisted of a singe row of teeth. Research suggests they didn't shed like modern sharks, instead they grew new teeth at the back of their mouth pushing older teeth to the tip of their jaws. Leidy is considered one of the founders of American vertebrate paleontology.
Edestus heinrichi was described in 1970 by John Strong Newberry and Amos Henry Worthen. Worthen was the second state geologist of Illinois and the first curator of the Illinois State Museum. The holotype was found in Illinois, but has been lost.
John Strong Newberry
A.H. Worthen
This specimen of Edestus heinrichi tooth and jaw was found in the Herrin Fm. near Lively Grove, IL. Lively Grove is in southern Illiniois, just southeast of St. Louis, MO.
