The Diplodocus was a dinosaur that lived in North America toward the end of the Jurassic period. It is generally believed to have been the longest of any known dinosaurs. This dinosaur’s tail was especially long. Interestingly enough, however, the Diplodocus had very short front legs compared to its back legs.
This was something that was fairly common amongst bipedal meat eating dinosaurs like the Tyrannosaurus Rex but this feature was pretty unique for a quadrupedal herbivore such as the Diplodocus. Nearly everything on the Diplodocus was long; its neck, tail, and hind legs ranked amongst the longest of any dinosaur but the front legs were much shorter in comparison.