The Smoky Hill Chalk Member and the Fort Hays Limestone Member combined make up the Niobrara Formation, a late Cretaceous period chalk formation that has been the origin of many Pteranodon discoveries. At the time it formed, this area would have been deep and remote ocean not close to any land. As a result of this remoteness, most fossils found in the Niobrara chalk are marine reptiles such as mosasaurs. Still, some non-avian dinosaurs have been discovered. It is theorized that these dinosaurs were carried by floodwaters and currents to the open ocean.