Tanycolagreus

Tanycolagreus was a predatory theropod that inhabited western North America during the Late Jurassic period, roughly 150 million years ago. Preserved in the Bone Cabin Quarry of Wyoming within the Morrison Formation, its remains include a remarkably intact skull and a large portion of the postcranial skeleton. Measuring between three and four metres in total length and weighing roughly one hundred kilograms, it was considerably larger than its close relative Coelurus. Its elongate limbs, modified nasal bones, and sharp, curved teeth point to an agile, fast-running pursuit hunter capable of bringing down medium-sized herbivorous dinosaurs or fast-moving prey. Because it shares traits with early tyrannosauroids as well as basal coelurosaurs, Tanycolagreus plays an essential role in resolving the evolutionary branching order of small-to-medium carnivores near the root of the coelurosaur radiation.

A complete skull and substantial skeleton make it one of the best understood Jurassic coelurosaurs.

Where and when

Tanycolagreus lived in the Late Jurassic, from 154 to 149 million years ago (Kimmeridgian age). Its remains come from United States, in the Morrison Formation.

The numbers

Length 3.7 m (estimates run from 3.3 to 4 m). Mass about 100 kg. Hip height about 1.2 m. That is 2.2 human-lengths, or 0.33 of a double-decker bus. These are estimates from partial skeleton; fields marked estimated by the site are length, mass, hip height.

Compare Tanycolagreus with a bus Place on the timeline