Fruitadens

Fruitadens is one of the smallest non-avian dinosaurs ever discovered, comparable in weight to a modern guinea pig. Uncovered in Late Jurassic rocks near Fruita, Colorado, this minuscule animal scurried under the feet of titanic sauropods like Brachiosaurus and Diplodocus. While originally collected in the 1970s, it was not formally named until 2010. The recovered skeletal elements show that adult individuals reached lengths of only around seventy centimetres. Its teeth display a blend of features, including tiny, serrated leaf-shaped crowns and small tusks, pointing towards an omnivorous or insectivorous diet rather than purely herbivorous browsing. As a fleet-footed biped, Fruitadens would have relied on agility and stealth to navigate the scrubby floodplains of the Morrison Formation, hunting invertebrates while avoiding small predators such as Coelurus and juvenile theropods.

Weighing well under one kilogram, it is one of the smallest known non-avian ornithischian dinosaurs.

Where and when

Fruitadens lived in the Late Jurassic, from 150.8 to 145.5 million years ago (Tithonian age). Its remains come from United States, in the Morrison Formation.

The numbers

Length 0.7 m (estimates run from 0.65 to 0.75 m). Mass about 0.63 kg. Hip height about 0.2 m. That is 0.4 human-lengths, or 0.06 of a double-decker bus. These are estimates from partial skeleton; fields marked estimated by the site are length, mass, hip height.

Compare Fruitadens with a bus Place on the timeline