Scutellosaurus

Scutellosaurus was a diminutive armoured dinosaur that lived in the arid floodplains of Early Jurassic North America. Measuring around one metre in length and weighing little more than a domestic dog, this agile herbivore represents one of the earliest recognised members of the thyreophoran lineage, the major branch that later evolved into the massive stegosaurs and ankylosaurs. Unlike its bulky descendants, Scutellosaurus was slender and capable of moving easily on two legs as well as four. It was protected by several hundred small, keeled bony plates called scutes embedded in rows along its neck, back, and extremely long tail. It relied on simple, leaf-shaped teeth to crop tender low-growing vegetation while remaining swift enough to evade contemporary predatory dinosaurs like Dilophosaurus.

It possessed hundreds of small bony studs along its back and an exceptionally long balancing tail.

Where and when

Scutellosaurus lived in the Early Jurassic, from 196 to 183 million years ago (Sinemurian-Pliensbachian age). Its remains come from United States, in the Kayenta Formation.

The numbers

Length 1.4 m (estimates run from 1.2 to 1.5 m). Mass about 9.2 kg. Hip height about 0.4 m. That is 0.8 human-lengths, or 0.13 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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