Fossil of the month from the KGS collection: Edestus

These are the giant teeth of an ancient shark which were found in a western Kentucky in February 2011. A roof-bolter working in the mine about 700 feet underground pulled this 300-million-year-old fossil from the roof. Although it looks like teeth in a jawbone, it is actually teeth in an unusual structure that was positioned in the middle of the jaw, between the mandibles of the jaw, like a saw. Because the skeletons of both ancient and modern sharks are mostly cartilage, they decay quickly after death, usually leaving teeth as their only remnants. Edestus is unusual in that it has this bone structure, called a whorl, which can be preserved with teeth. Several species of Edestus with different shaped teeth lived in the Pennsylvanian Period, the so-called "Coal Age." KGS has several Edestus whorls in its collection.

This fossil made news around the country when KGS and the University of Kentucky disseminated a news release about the find. The April 2011 news release is still available on the KGS website.

Chuck Ciampaglio and Mike Taylor, of Wright State University’s Earth and Environmental Sciences Department, later made replicas of the specimen. To create the replicas, a mold of the fossil was made using a material known as Dragon Skin, and a casting material was poured into the mold and allowed to cure and harden. The results were nearly perfect replicas that Taylor carefully painted to closely match the original. They are on display at KGS.

With so little of the skeletons of Edestus available, there is plenty of debate among paleontologists about how the ancient shark appeared. KGS geologist Steve Greb drew these depictions of what the creature may have looked like when roaming the shallow sea in this region 300 million years ago.

 

 

Last Modified on 2017-04-05
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