Frankfurt am Main - Senkenberg Museum - Diplodocus und Edmontosaurus
Diplodocus is a genus of diplodocid sauropod dinosaur whose fossils were first discovered in 1877 by S. W. Williston. The generic name, coined by Othniel Charles Marsh in 1878, is a Neo-Latin term derived from Greek διπλόος (diploos) "double" and δοκός (dokos) "beam", in reference to its double-beamed chevron bones located in the underside of the tail. These bones were initially believed to be unique to Diplodocus; however, they have since then been discovered in other members of the diplodocid family and in non-diplodocid sauropods such as Mamenchisaurus.
It lived in what is now western North America at the end of the Jurassic Period. Diplodocus is one of the more common dinosaur fossils found in the Upper Morrison Formation, a sequence of shallow marine and alluvial sediments deposited about 155 to 148 million years ago, in what is now termed the Kimmeridgian and Tithonian stages Diplodocus itself ranged from about 154 to 150 million years ago. The Morrison Formation records an environment and time dominated by gigantic sauropod dinosaurs such as Camarasaurus, Barosaurus, Apatosaurus and Brachiosaurus.
Diplodocus is among the most easily identifiable dinosaurs, with its classic dinosaur shape, long neck and tail and four sturdy legs. For many years, it was the longest dinosaur known. Its great size may have been a deterrent to the predators Allosaurus and Ceratosaurus: their remains have been found in the same strata, which suggests they coexisted with Diplodocus.
Edmontosaurus is a genus of crestless hadrosaurid (duck-billed) dinosaur. It contains two species: Edmontosaurus regalis and Edmontosaurus annectens. Fossils of E. regalis have been found in rocks of western North America that date from the late Campanian stage of the Cretaceous Period 73 million years ago, while those of E. annectens were found in the same geographic region but in rocks dated to the end of the Maastrichtian stage of the Cretaceous, 65.5 million years ago. E. annectens was one of the last non-avian dinosaurs, and lived alongside Triceratops horridus and Tyrannosaurus rex shortly before the Cretaceous–Paleogene extinction event.
Skeleton of Edmontosaurus annectens collected 1924, at the Royal Ontario Museum
Edmontosaurus included some of the largest hadrosaurid species, measuring up to 12 meters long and weighing around 4.0 metric tons. Several well-preserved specimens are known that include not only bones, but in some cases extensive skin impressions and possible gut contents. It is classified as a genus of saurolophine (or hadrosaurine) hadrosaurid, a member of the group of hadrosaurids which lacked hollow crests.