Diplodocus now common scientific opinion that "Seismosaurus hallorum" is a species of "Diplodocus". This genus of dinosaurs lived in what is now mid-western North America at the end of the Jurassic period. "Diplodocus" is one of the more common dinosaur fossils found in the middle to upper Morrison Formation, between about 154 and 152 million years ago, during the late Kimmeridgian age. The Morrison Formation records an environment and time dominated by gigantic sauropod dinosaurs, such as "Apatosaurus", "Barosaurus", "Brachiosaurus", "Brontosaurus", and "Camarasaurus". "Diplodocus" is among the most easily identifiable dinosaurs, with its typical sauropod shape, long neck and tail, and
Wyoming Dinosaur Center on the property is from the "Something Interesting" or SI excavation site. This site presents the rare occurrence of both dinosaur trace fossils and body fossils including footprints of many Sauropods and "Allosaurus" as well as skeletal remains from "Camarasaurus, Diplodocus," and "Apatosaurus" - three of the sauropods most common in the area during the Late Jurassic. Most of the bones belong to a juvenile (30 foot long) "Camarasaurus" that was scavenged by many "Allosaurs". This is known based on the presence of both teeth and claw marks on many of the bones present as well as an abundance of