Aquilops

Aquilops was a diminutive, early horned dinosaur known from an exquisitely preserved partial skull discovered in the Cloverly Formation of Montana. Reaching only sixty centimetres in length and weighing approximately two kilograms, it had an adult skull smaller than that of a domestic rabbit. Named for its sharply hooked rostral bone, Aquilops lived during the Early Cretaceous period and stands as the earliest definitive neoceratopsian yet discovered in North America. Its evolutionary relationships firmly link it to contemporary Asian species, demonstrating that small horned dinosaurs migrated across intercontinental land bridges long before their gigantic horned descendants came to dominate Late Cretaceous ecosystems. Based on its slender jaws and small stature, Aquilops probably cropped delicate tender vegetation while relying on keen senses to avoid contemporaneous predators like Deinonychus.

It is the earliest definitive neoceratopsian discovered in North America, predating larger horned dinosaurs by millions of years.

Where and when

Aquilops lived in the Early Cretaceous, from 109 to 104 million years ago (Albian age). Its remains come from United States, in the Cloverly Formation.

The numbers

Length 0.6 m. Mass about 1.7 kg. Hip height about 0.2 m. That is 0.4 human-lengths, or 0.05 of a double-decker bus. These are estimates from partial skeleton; fields marked estimated by the site are length, mass, hip height.

Compare Aquilops with a bus Place on the timeline