Diplodocus, the "double-beam," is  one of the most famous dinosaurs in the world. This 24-meter-long, four- meter-tall dinosaur can be found in dozens of museums worldwide, making "Dippy" recognizeable everywhere. Its absurdly long tail is perhaps its most iconic feature: it tapers  to a flexible "whip-like" end, which  some enthusiasts speculate could  have been used as a real whip against predators. This tail also functioned as a counterbalance to  the massive, heavy neck that stretched from the front of its  body. While some sauropods like  Brachiosaurus had longer arms than  legs, giving them more vertical post- ures, Diplodocus's arms were shorter,  giving it a horizontal posture.  This hefty herbivore browsed the  Jurassic foliage of semi-arid coasts in what is now the central United States. Diplodocus lived alongside several other sauropods, including Apatosaurus and Camarasaurus, so the landscape must have been constantly altered wherever these hungry diners stopped to enjoy the buffet. Based on the shape of their teeth, paleon- tologists can tell that each species of sauropod ate a different kind of  plant in order to avoid competition with each other. Many predators (such as Allosaurus, Ceratosaurus,  and Torvosaurus) also shared the  same habitat with these sauropods, and would have had to eat different prey to avoid competition as well.