Lycorhinus

Lycorhinus was a basal heterodontosaurid dinosaur that lived in what is now South Africa during the Early Jurassic period. When its fossil lower jaw was initially described in the 1920s, palaeontologists mistakenly classified it as a cynodont, a group of mammal-like reptiles, because of its prominent canine-like tusk. It was only decades later that its true identity as an early ornithischian dinosaur was established. Estimated to be around one metre in length and weighing just a few kilograms, it was a lightweight, fast-running biped. The cheek teeth were tightly packed and adapted for chewing vegetation, while the front tusks may have served in intraspecific display, defence, or opportunistically processing diverse food sources. Although known mainly from partial jaw material, Lycorhinus remains an important taxon for understanding the early diversity and dental evolution of ornithischians.

It was originally mistaken for a mammal-like cynodont reptile due to its prominent canine-like tooth.

Where and when

Lycorhinus lived in the Early Jurassic, from 200 to 195 million years ago (Hettangian-Sinemurian age). Its remains come from South Africa, in the Elliot Formation.

The numbers

Length 1.2 m (estimates run from 1.1 to 1.3 m). Mass about 3.9 kg. Hip height about 0.45 m. That is 0.7 human-lengths, or 0.11 of a double-decker bus. These are estimates from fragmentary remains; fields marked estimated by the site are length, mass, first ma, last ma, hip height.

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