Dinosaurs / Jurassic / Chaoyangsaurus
Chaoyangsaurus
Jurassic chao-YAHNG-sawr-us, “Chaoyang lizard”
Chaoyangsaurus was a primitive horned dinosaur from the Late Jurassic period, uncovered in the Tuchengzi Formation of Liaoning, China. Measuring just over one metre in length and weighing perhaps ten kilograms, it lived far before its massive, quadrupedal descendants like Triceratops. Unlike later relatives, Chaoyangsaurus walked predominantly on two slender hind legs and possessed short forelimbs. Its skull featured an incipient frill at the back and a small, pointed rostral bone at the tip of the snout. These skull features demonstrate how the distinctive parrot-like beak and neck shield of the ceratopsians first began to take shape. While its remains were discovered in the late twentieth century, taxonomic studies in the 1990s formally confirmed its vital position near the very root of ceratopsian evolutionary history.
It is one of the earliest recognised ceratopsians, possessing a rudimentary frill and parrot-like beak.
Where and when
Chaoyangsaurus lived in the Late Jurassic, from 152 to 145 million years ago (Tithonian age). Its remains come from China, in the Tuchengzi Formation.
The numbers
Length 1.1 m (estimates run from 1 to 1.1 m). Mass about 8.5 kg. Hip height about 0.35 m. That is 0.6 human-lengths, or 0.1 of a double-decker bus. These are estimates from partial skeleton; fields marked estimated by the site are length, mass, first ma, last ma, hip height.