Dicraeosaurus

Dicraeosaurus (Gr. , ' "bifurcated, double-headed" + Gr. , ' "lizard") is a genus of diplodocoid sauropod dinosaur that lived in what is now Lindi Region, Tanzania during the late Jurassic period. The genus was named for the neural spines on the back of its neck. The first fossil was described by paleontologist Werner Janensch in 1914.

==Description== thumb|left|Restoration of D. hansemanni thumb|left|Size comparison of Dicraeosauridae. D. hansemanni in brown, D. sattleri in red. Unlike most diplodocoids, Dicraeosaurus had a comparatively large head with a relatively short and wide neck. The neck contained 12 unusually short vertebrae, likely indicating a low-level browser of vegetation no more than off the ground. Dicraeosaurus also lacked the "whiplash" tail tip typical of diplodocoids. It was smaller than many other diplodocoids, at only in length and , though this still makes it among the larger known members of the family Dicraeosauridae. The genus is notable for the rather tall neural spines protruding from its vertebrae, which it is named for. They were not straight as in some members of the family, instead forming a rough "Y" shape. These spines likely provided muscle attachment points.