Diplodocus is a huge dinosaur from the same time as the Allosaurus. It lived during the Upper Jurassic period, about 145 to 155 million years ago. It was a vegetarian, eating mostly leaves with its peg-like teeth.
Temporal range: Upper Jurassic
Diplodocus was a long-necked, whip-tailed giant and could grow up to 27 m long. It had an 8 m long neck and 14 m long tail. Its weight was approximately 22,680 kg. It had a short 6 ft long head. Its size helped protect it from other dinosaurs. It used its long neck to poke into forests because its body was too big. It is also believed to have knocked the trees down. The longest species is the hallorum, which was thought to be the longest of all dinosaurs (now Amphicoelias).
Diplodocus skeletons are among the longest dinosaur skeletons ever found. Fossils were discovered in Western North America, particularly in the Rocky Mountains of the western USA. A complete tail has never been found.
Seismosaurus was the longest animal ever known, but paleontologists found they had misplaced vertebrae, making the body too long. Current length estimates are 33–36 metres long. Weight estimates vary from 40 to 60 tonnes. Weight estimates of other Diplodocus species are much lower: 10 to 17 tonnes.
- Lucas S. et al 2004. Reappraisal of Seismosaurus, a late Jurassic sauropod dinosaur from New Mexico. Archived 2019-10-08 at the Wayback Machine The Geological Society of America, 2004 Denver Annual Meeting.
- Foster J.R., ed. (2006). "Taxonomic status of Seismosaurus hallorum, a late Jurassic sauropod dinosaur from New Mexico". Paleontology and geology of the Upper Morrison Formation. Bulletin. New Mexico Museum of Natural History and Science (bulletin 36). pp. 149–161. ISSN 1524-4156.