Temporal range: Late Jurassic, 155–150 Ma
Dicraeosaurus was a small diplodocid that had many physical differences from the rest of the family. It was named for the spines on the back of the neck. Diplodocids were sauropods with long necks and tails, skinny bodies and limbs, and tiny brains and heads. They were light in relevance to the brachiosaurs, because their vertebrae were a lattice of bony struts, used to reduce weight and take maximum stress. They lived worldwide in the Late Jurassic and Cretaceous. Examples of diplodocids are Apatosaurus, Diplodocus, and Mamenchisaurus. The first fossil was discovered by paleontologist Werner Janensch in 1914.