The brachiosaur giants of the Morrison and Tendaguru with a description of a new subgenus, Giraffatitan, and a comparison of the world's largest dinosaurs

Abstract

A new skeletal restoration of Brachiosaurus brancai shows that this gracile, giraffe-like taxon is a distinct subgenus from Brachiosaurus altithorax. Ultrasaurus macintoshi is a junior synonym of B. altithorax and is similar in size to the largest B. brancai specimen. A survey of exceptionally large sauropod remains indicates that the largest weighed about 50 tons in lean condition, but this size was probably not the ultimate limit of the group. "Ultrasaurus" was not larger than the largest African brachiosaurs and published estimates of body weight up to 190 tons are unwarranted exaggerations.