Small toy brachiosaurus.
Brachiosaurus is a genus of sauropod dinosaur that lived in North America during the Late Jurassic, about 154–153 million years ago. Brachiosaurus is estimated to have been between 18 and 21 meters (59 and 69 ft) long; weight estimates range from 28.3 to 58 metric tons (31.2 and 64 short tons). It had a disproportionately long neck, small skull, and large overall size, all of which are typical for sauropods. Atypically, Brachiosaurus had longer forelimbs than hindlimbs, which resulted in a steeply inclined trunk, and a proportionally shorter tail.