Diplodocus was a long-necked, whip-tailed giant, measuring about 90 feet (27 m) long with a 26 foot (8 m) long neck and a 45 foot (14 m) long tail, but its head was less than 2 feet long. It was among the longest land animals ever. Its nostrils were at the top of its head and it had peg-like teeth, but only in the front of the jaws. Its front legs were shorter than its back legs, and all had elephant-like, five-toed feet. One toe on each foot had a thumb claw, probably for protection. A fossilized Diplodocus skin impression reveals that it had a row of spines running down its back. Diplodocus was more lightly built than the other giant sauropods, and may have weighed only about 10-20 tons. Its backbone had extra bones underneath it, which had bony protrusions running both forwards and backwards (anvil shaped), a “double-beam”, probably for support and extra mobility of its neck and tail. It may have used its whip-like tail for protection. A recent Diplodocus skin impression was found, showing a row of spines running down the back. It has been determined that Diplodocus (and the other diplodocid sauropods, like Apatosaurus) could not hold their necks over about 17 feet (5.4 m) off the ground (Parrish and Stevens,1999). Gastralia (hanging belly ribs) are thin, fragile ribs that helped support and protect the internal organs (like the lungs) in the middle area of the body. These ribs were not attached to the backbone; they were attached to the skin in the belly area. It used to be thought that the sauropods (like Diplodocus, Brachiosaurus and Apatosaurus) and Stegosaurus had a second brain. Paleontologists now think that what they thought was a second brain was just an enlargement in the spinal cord in the hip area. This enlargement was larger than the animal’s tiny brain. Diplodocus was a sauropod, whose intelligence was the among the lowest of the dinosaurs.
