Brontosaurus
Choose Brontosaurus and you get a 20-metre body, a neck as thick as a tree trunk and a tail like a bullwhip – plus a century-long identity crisis.
Dead, then alive again
Othniel Charles Marsh named Apatosaurus in 1877 and Brontosaurus in 1879, during the frantic “Bone Wars” rivalry with Edward Drinker Cope. In 1903 Elmer Riggs concluded the two were the same genus, and because Apatosaurus was named first, Brontosaurus officially disappeared – though museums, films and a 1989 US postage stamp kept the name alive.
In 2015 a large specimen-by-specimen study by Emanuel Tschopp and colleagues found enough differences to restore Brontosaurus, with three species: B. excelsus, B. parvus and B. yahnahpin. Many researchers accept this, but the line between Brontosaurus and Apatosaurus remains narrow and some still argue they belong together.
Heavyweight of the Morrison plains
Brontosaurus lived in the Late Jurassic Morrison Formation of the western United States, about 156–146 million years ago, sharing floodplains with Diplodocus, Stegosaurus and Allosaurus. It was a stocky apatosaurine: roughly 20–22 metres long, with an estimated mass of about 15 tonnes or more and an unusually deep, robust neck.
Your neck was probably held fairly low, sweeping across ground plants and shrubs rather than towering skyward. Like other sauropods you would hatch from an egg perhaps the size of a grapefruit or smaller and grow very fast. Bone studies of apatosaurines suggest they reached near-adult size in roughly 10–15 years.
The whip and the wrong head
The long tail tapered into a thin, whip-like end. Computer models suggest apatosaurines may have been able to crack it fast enough for the tip to approach or even exceed the speed of sound – an intriguing but untested idea.
For decades many mounted skeletons wore the wrong head: a short, boxy skull borrowed from Camarasaurus. Only in the late 1970s were they given the longer, Diplodocus-like skulls that really belong to apatosaurines.
