Smoky Hill Chalk

[2] It is underlain by the Fort Hays Limestone Member and overlain by the Pierre Shale.

[2] The Smoky Hill Chalk 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.

Another excellent skeleton of Xiphactinus audax was collected by Edward Drinker Cope during the late nineteenth century heyday of American paleontology and its Bone Wars.