The word dinosaur was coined by Richard Owen in 1841, deinos (terrible) + sauros (lizard) which describe various extinct reptiles of the orders Saurischia and Ornithischia that flourished during the Mesozoic Era. Dinosaurs were carnivorous or herbivorous, dwelled mostly on land, and varied from the size of a small dog to the largest land animals that ever lived. Diplodocids, or Diplodocidae (double beams), are a group of sauropod dinosaurs. Diplodocus was a long-necked, whip-tailed giant, measuring about 90 feet long with a 26 foot long neck and a 45 foot long tail, but its head was less than 2 feet long. A genus of diplodocid sauropod dinosaur whose fossils were first discovered in 1877 by S. W. Williston. It lived in what is now western North America at the end of the Jurassic Period. Diplodocus is among the most easily identifiable dinosaurs, with its classic dinosaur shape, long neck and tail and four sturdy legs. Shown here is Hatcher's original restoration of a D. carnegii skeleton from 1901.