14.2" Cretaceous Swordfish (Protosphyraena) Pectoral Fin - Kansas

This is a 14.2" long, fossilized, pectoral fin of a large, Cretaceous swordfish (Protosphyraena). It was collected from the Smoky Hill Chalk in Gove County, Kansas.

Protosphyraena is a fossil genus of swordfish-like marine fish that had a worldwide distribution during the Upper Cretaceous Period. Though fossil remains of this taxon have been found in both Europe and Asia, it is perhaps best known from the Smoky Hill Member of the Niobrara Chalk Formation of Kansas. Protosphyraena was a large fish, averaging 2–3 meters in length. It shared the Cretaceous oceans with aquatic reptiles, such as mosasaurs and plesiosaurs, as well as with many other species of extinct predatory fish.



The Smoky Hill Chalk Member of the Niobrara Chalk formation is a Cretaceous conservation Lagerstätte, or fossil rich geological formation, known primarily for its exceptionally well-preserved marine reptiles. It outcrops in parts of northwest Kansas, its most famous localities for fossils, and in southeastern Nebraska. Large well-known fossils excavated from the Smoky Hill Chalk include marine reptiles such as plesiosaurs, large bony fish such as Xiphactinus, mosasaurs, flying reptiles or pterosaurs (namely Pteranodon), flightless marine birds such as Hesperornis, and turtles. Many of the most well-known specimens of the marine reptiles were collected by dinosaur hunter Charles H. Sternberg and his son George.