Brachiosaurus vs. Brontosaurus

Main Difference

The main difference between Brachiosaurus and Brontosaurus is that the Brachiosaurus is a genus of dinosaur and Brontosaurus is a genus of reptiles (fossil).

• Brachiosaurus

  Brachiosaurus is a genus of sauropod dinosaur that lived in North America during the Late Jurassic, about 154–153 million years ago. It was first described by American paleontologist Elmer S. Riggs in 1903 from fossils found in the Grand River Canyon (now Colorado River) of western Colorado, in the United States. Riggs named the dinosaur Brachiosaurus altithorax, declaring it “the largest known dinosaur”. The generic name is Greek for “arm lizard”, in reference to its proportionately long arms, and the specific name means “deep chest”. Brachiosaurus had a disproportionately long neck, small skull, and large overall size, all of which are typical for sauropods. However, the proportions of Brachiosaurus are unlike most sauropods: the forelimbs were longer than the hindlimbs, which resulted in a steeply inclined trunk, and its tail was shorter in proportion to its neck than other sauropods of the Jurassic.

  Brachiosaurus is the namesake genus of the family Brachiosauridae, which includes a handful of other similar sauropods. Most popular depictions of Brachiosaurus are in fact based on Giraffatitan, a species of brachiosaurid dinosaur from the Tendaguru Formation of Tanzania that was originally described by German paleontologist Werner Janensch as a species of Brachiosaurus, B. brancai. Recent research shows that the differences between the type species of Brachiosaurus and the Tendaguru material are significant enough that the African material should be placed in a separate genus. Several other potential species of Brachiosaurus have been described from Africa and Europe, but none of them are currently thought to belong to Brachiosaurus.

  Brachiosaurus is one of the rarer sauropods of the Morrison Formation. The type specimen of B. altithorax is still the most complete specimen, and only a relative handful of other specimens are thought to belong to the genus. It is regarded as a high browser, probably cropping or nipping vegetation as high as possibly 9 metres (30 ft) off the ground. Unlike other sauropods, it was unsuited for rearing on its hindlimbs. It has been used as an example of a dinosaur that was most likely ectothermic because of its large size and the corresponding need for sufficient forage, but more recent research finds it to have been warm-blooded.

• Brontosaurus

  Brontosaurus ( bron-tə-SAWR-əs), meaning “thunder lizard” (from Greek βροντή, brontē = thunder + σαῦρος, sauros = lizard), is a genus of gigantic quadruped sauropod dinosaurs. Although the type species, B. excelsus, had long been considered a species of the closely related Apatosaurus, more recent research has proposed that Brontosaurus is a genus separate from Apatosaurus that contains three species: B. excelsus, B. yahnahpin, and B. parvus.Brontosaurus had long, thin necks and small heads, adapted for a herbivorous lifestyle; a bulky, heavy torso; and long, whip-like tails. The various species lived during the Late Jurassic epoch in the Morrison Formation of North America, going extinct by the end of the Jurassic. Adult individuals of Brontosaurus are estimated to weigh up to 15 tonnes (15 long tons; 17 short tons) and measure up to 22 metres (72 ft) long.

  As the archetypal sauropod, Brontosaurus is one of the best-known dinosaurs, and has been featured in film, advertising, and postage stamps, as well as many other types of media.