Dacentrurus

Dacentrurus was a large, heavily built stegosaur that inhabited Western Europe during the Late Jurassic. First described by Sir Richard Owen under the name Omosaurus in 1875, it was later renamed because that moniker was already in use for a fossil crocodile. Reaching up to eight or nine metres in length and weighing several tonnes, Dacentrurus rivalled Stegosaurus in sheer size. It was characterised by an exceptionally wide pelvis and a row of paired plates on its neck that transitioned into pairs of formidable spines along the lower back and tail. Unlike many later stegosaurs, its limbs were somewhat shorter and wider, reflecting a very stocky quadrupedal frame. It browsed on tough low vegetation in island ecosystems across what are now Britain, France, and the Iberian Peninsula.

It was the first stegosaur ever discovered and described, originally given the preoccupied name Omosaurus by Richard Owen.

Where and when

Dacentrurus lived in the Late Jurassic, from 154.8 to 149.2 million years ago (Kimmeridgian age). Its remains come from United Kingdom and Portugal and Spain and France, in the Kimmeridge Clay Formation.

The numbers

Length 8 m (estimates run from 7 to 9 m). Mass about 3.9 t. Hip height about 2.2 m. That is 4.7 human-lengths, or 0.71 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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