Diplodocus, which takes its meaning from the Greek language and roughly translated, is “double-beamed giant lizard”, was a sauropod of incredible size. Based on fossilized skeletal remains, it has been estimated that these dinosaurs routinely reached lengths of 90 – 100 feet and stood tall enough to graze upon the leafy tops of the trees during the Jurassic period. They have become possibly the most widely recognized dinosaur in our culture because of its classic dinosaur shape: long tail, long neck, small head, and 4 thick & sturdy legs. Diplodocus lived in the western states of North America, and their fossilized remains are quite commonly found in Utah, Colorado, and Wyoming. Thanks to the abundant resources geologists have had to study, quite a bit is known about this huge animal:
1. Name – Diplodocus is actually the genera; there are now 4 species of Diplodocus that have been defined. The name Diplodocus was coined by Othniel Charles Marsh in 1878 and referred to the double-beam or chevron-like formation of the underside of the vertebrae making up the tail. At the time, it was believed that that particular construction was unique to that dinosaur, but similar constructions have since been found in other species of large sauropods. During the later period of the Jurassic age, very large sauropods roamed the earth, eating the greenery and subsisting on a totally herbivorous diet. It has been suggested by many scientists that the sheer size of these dinosaurs kept away the predatory, carnivorous species.
2. Size – Diplodocus is more slender in build than some of the other large sauropods, such as Brachiosaurus and Apatosaurus. It had as many as 80 vertebrae in its long, whip-like tail; almost twice as many as other dinosaurs. Due to the unique construction of the tail vertebrae, there has been a lot of speculation in the scientific community as to whether Diplodocus could whip its tail and cause it to make noise. The tail also probably served as a counterbalance for the extremely long neck. Perhaps the double construction of some of the vertebrae in the tail would have been to support the blood vessels and nerves or to protect these important internal systems from damage if the tail was laid on the ground, which would have created excess weight. Estimates put the greatest length these animals attained at 115 feet, 20 feet of which would have been all neck. Weight-wise, the estimated range is 11.0 – 17.6 tons. The skull of Diplodocus was relatively small in relation to the rest of it, and the nostrils were small and located high up on top of the head, almost between the eyes, leading scientists to speculate as to whether the animal could have been aquatic, and could breathe by just poking its head slighty above the surface. This anatomy is seen today in the elephant, which has led some to propose that Diplodocus may have had a trunk, but others disagree with that theory. The legs of Diplodocus were thick and sturdy, to support the animal, with the front legs being slightly shorter than the hind legs. In early illustrations from the 19th century, Diplodocus was often portrayed as extending its neck up all the way, but more recent studies based on computer modelling suggest that the dinosaur most likely stayed in a more horizontal position, with the neck and tail balancing each other. There was also a study done at Columbia University in 1992 that showed Diplodocus would have had to have a heart weighing 1.6 tons to pump the blood all the way up the neck to reach the animal’s skull, unless there were auxilliary heart structures in the neck to help with the pumping.
3. Diet – Diplodocus had unusual teeth for a dinosaur: they were small and peg-like. The wear patterns on the tooth fossils show that Diplodocus probably ate by stripping the foliage off the stems or branches of plants. The extra-long neck and the location of the nostrils suggest that Diplodocus was very fond of aquatic plants and could reach underwater to get at food, and there is strong evidence that the animals may have dwelt near rivers. They had a crop digestion system, and small stones to aid in digestion, “gastroliths”, have been found along with skeletons.
4. Reproduction – Hardy anything is known about the reproductive habits of Diplodocus; there is no evidence in the fossil record about their nesting habits and it is very rare for dinosaur eggs to be fossilized. A lot of the conjectured knowledge is drawn from what is known about other sauropods . Other species laid their eggs communally in shallow pits which they then covered with vegetation; Diplodocus may have behaved in the same manner. It is now known that other sauropods grew very fast and reached sexual maturity within a decade, and then continued growing throughout the rest of life, when it was earlier believed that it took decades for them to even reach that stage.
5. Museums – There are several full skeletons of Diplodocus on display in museums throughout the world. Actually, they are not the real skeletal remains, but casts made of them, which were donated to several museums by Andrew Carnegie at the beginning of the 20th century. Mr. Carnegie is credited with making Diplodocus so familiar to modern culture. Diplodocus skeletons or replicas are still displayed at the Carnegie Natural History Museum in Pittsburgh, the Natural History Museum in London, the Zoological Museum of the Russian Academy of Sciences in St. Petersburg, Russia, and museums in France, Spain, Argentina, Mexico, Germany, and Italy.