Barosaurus

Barosaurus was an extraordinarily long-necked sauropod dinosaur from the Late Jurassic Morrison Formation of North America, living roughly 150 million years ago. While sharing many anatomical features with Diplodocus, it differed substantially in its proportions: its neck was much longer while its tail was relatively shorter. Its neck vertebrae were exceptionally elongated and hollowed out by internal air sacs to reduce weight. The famous mounted skeleton in the American Museum of Natural History depicts an adult rearing up on its hind legs to protect its young from an attacking Allosaurus, though whether it could truly rear in life remains actively debated. It fed on mid- to high-level vegetation across ancient floodplains.

Its sixteen neck vertebrae were extraordinarily long, giving it a neck that accounted for roughly a third of its entire length.

Where and when

Barosaurus lived in the Late Jurassic, from 155 to 148 million years ago (Kimmeridgian-Tithonian age). Its remains come from United States, in the Morrison Formation.

The numbers

Length 26 m (estimates run from 24 to 27 m). Mass about 17 t. Hip height about 4.5 m. That is 15 human-lengths, or 2.28 of a double-decker bus. These are estimates from partial skeleton; fields marked estimated by the site are length, mass, hip height.

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