Brontosaurus
"Brontosaurus" was a large, long-necked quadrupedal animal with a long, whip-like tail, and forelimbs that were slightly shorter than its hindlimbs. The largest species, "B. excelsus", weighed up to and measured up to long from head to tail. For comparison, the current largest land animal, the average male African bush elephant is 3.20 m (10.5 ft) tall at the shoulder and has a body mass of 6,000 kg (13,228 lb) or 6.6 short tons.
Sauropoda
Among the smallest sauropods were the primitive "Ohmdenosaurus" (4 m, or 13 ft long), the dwarf titanosaur "Magyarosaurus" (6 m or 20 ft long), and the dwarf brachiosaurid "Europasaurus", which was 6.2 meters long as a fully-grown adult. Its small stature was probably the result of insular dwarfism occurring in a population of sauropods isolated on an island of the late Jurassic in what is now the Langenberg area of northern Germany. The diplodocoid sauropod "Brachytrachelopan" was the shortest member of its group because of its unusually short neck. Unlike other sauropods, whose necks could grow to up to four times the length of their backs, the neck of "Brachytrachelopan" was shorter than its backbone.