Brachylophosaurus

Brachylophosaurus was a mid-sized hadrosaurid dinosaur known from Campanian deposits of Alberta and Montana. It reached around nine metres in length and was characterised by an unusual flat, paddle-shaped bony crest running backward over the roof of its skull. Unlike the hollow crests of lambeosaurines, this solid structure was strictly used for visual signalling. The animal is especially celebrated among palaeontologists due to several astonishingly preserved natural mummies, most notably a subadult specimen named Leonardo found in 2000. This individual retained complete impressions of pebbly scales across its body, indications of soft neck frills, muscular contours, and even fossilised remnants of its last meal, which included leaves, seeds, and conifer needles. Brachylophosaurus provides one of the clearest windows into the true living appearance and diet of duck-billed dinosaurs.

A remarkably mummified specimen nicknamed Leonardo preserved extensive skin impressions, muscle outlines, and stomach contents.

Where and when

Brachylophosaurus lived in the Late Cretaceous, from 78 to 75 million years ago (Campanian age). Its remains come from Canada and United States, in the Judith River Formation.

The numbers

Length 8.8 m (estimates run from 8.5 to 9 m). Mass about 3.5 t. Hip height about 2.8 m. That is 5.2 human-lengths, or 0.79 of a double-decker bus. These are estimates from near-complete skeleton; fields marked estimated by the site are length, mass, hip height.

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