Brontosaurus

Brontosaurus was a heavily built diplodocid sauropod that inhabited North America during the Late Jurassic period, roughly 152 million years ago. Reaching over twenty metres in length and weighing around seventeen tonnes, it was slightly more slender than its close relative Apatosaurus, but still possessed an extraordinarily deep, muscular neck and robust limbs. Famous since its discovery during the Bone Wars by Othniel Charles Marsh, it was lumped into Apatosaurus for over a century due to perceived minor differences. However, an exhaustive anatomical study published in 2015 concluded that Brontosaurus exhibits distinct structural differences in its cervical vertebrae and shoulder girdle, justifying its revival as a valid and beloved genus.

Long considered a junior synonym of Apatosaurus, a detailed statistical study in 2015 revived it as a distinct genus.

Where and when

Brontosaurus lived in the Late Jurassic, from 155 to 150 million years ago (Kimmeridgian age). Its remains come from United States, in the Morrison Formation.

The numbers

Length 22 m (estimates run from 21 to 23 m). Mass about 17 t. Hip height about 4.5 m. That is 12.9 human-lengths, or 1.96 of a double-decker bus. These are estimates from partial skeleton; fields marked estimated by the site are length, mass, hip height.

Compare Brontosaurus with a bus Place on the timeline