Ceratosaurus

Ceratosaurus was an unmistakable predatory dinosaur that lived during the Late Jurassic alongside Allosaurus and Torvosaurus. Measuring between five and seven metres in length, it possessed a large skull dominated by a prominent midline horn core on its nasal bones and smaller ridges over its eyes. Uniquely among theropods, a single continuous row of small bony scutes ran down the midline of its spine. Ceratosaurus was armed with exceptionally long, blade-like upper teeth, a deep, flexible tail resembling that of a crocodile, and four-fingered hands. These features have led some palaeontologists to suggest it may have frequented waterways to ambush aquatic prey, though it was equally capable of hunting terrestrial herbivorous dinosaurs.

It had a row of small bony osteoderms running right down the middle of its back.

Where and when

Ceratosaurus lived in the Late Jurassic, from 155 to 145 million years ago (Kimmeridgian-Tithonian age). Its remains come from United States and Portugal, in the Morrison Formation.

The numbers

Length 6.3 m (estimates run from 5.5 to 7 m). Mass about 710 kg. Hip height about 1.9 m. That is 3.7 human-lengths, or 0.56 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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