Wuerhosaurus

Wuerhosaurus was one of the few stegosaurs known to have survived well into the Early Cretaceous period, long after most other members of the family had vanished. Discovered in Xinjiang, China, it is represented by partial skeletons that show notable evolutionary differences from Jurassic forms. Measuring up to seven metres in length, Wuerhosaurus had a low-slung body with forelimbs that were quite short compared to its hindlimbs, positioning its small head close to the ground for grazing. Its dermal plates were unusually low and elongated rather than tall and pointed, though some researchers suggest their edges were simply broken before fossilisation. A formidable set of tail spikes was present for defence against predatory theropods like Kelmayisaurus in its floodplain ecosystem.

It was one of the last surviving stegosaurs, living well into the Early Cretaceous long after most relatives died out.

Where and when

Wuerhosaurus lived in the Early Cretaceous, from 137 to 125 million years ago (Valanginian-Aptian age). Its remains come from China, in the Tugulu Group.

The numbers

Length 6.8 m (estimates run from 6.5 to 7 m). Mass about 3.2 t. Hip height about 2 m. That is 4 human-lengths, or 0.61 of a double-decker bus. These are estimates from partial skeleton; fields marked estimated by the site are length, mass, first ma, last ma, hip height.

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