Dinosaur, a medium-sized sauropod whose remains were found in Tanzania and dated to the late Jurassic period. The name Dicraeosaurus means roughly "two-forked lizard," in reference to the tall, forked spines jutting from its vertebrae. Two species of this genus are known: D. hansemanni and D. sattleri.

Dicraeosaurus stood about 6 meters tall on four legs and reached lengths of 13 to 20 meters. Not particularly bulky, it probably didn't weigh more than 6 tons. It was a herbivore, similar in basic form to Diplodocus, though its neck was shorter than Diplodocus' and somewhat stunted relative to its own long, powerful tail. The prominent spines on its back (which were probably used to support muscles, and didn't form fins) made it seem even taller than it was, and may have served as a deterrent to predators.

Order: Saurischia
Suborder: Sauropodomorpha
Infraorder: Sauropoda
Family: Diplodocidae