Overview
Agilisaurus (literally "agile lizard") is a genus of small ornithischian dinosaur that lived during the Middle Jurassic in what is now eastern Asia. It is generally interpreted as a basal member of the group that later produced the more familiar ornithopods. For general context see ornithischian treatments and broader dinosaur summaries.
Physical characteristics
Agilisaurus was lightly built and adapted for nimble movement. Features typically emphasized by researchers include a relatively long tail for balance, elongated hindlimbs suggesting good running ability, and forelimbs capable of grasping or supporting weight when needed. The skull was small with leaf-shaped teeth suitable for a herbivorous diet.
- Small body size and low mass
- Bipedal to facultatively quadrupedal stance
- Leaf-shaped teeth indicating plant-eating
- Long, stiffened tail for balance
Discovery and naming
Fossils now attributed to Agilisaurus were first discovered in Sichuan Province; initial finds date back to 1915, with more complete specimens recovered and studied later in the 20th century. The genus name reflects the animal's inferred agility. Material from the Middle Jurassic helps place the animal in regional faunas of that interval and within eastern Asian ecosystems (eastern Asia).
Paleobiology and importance
Agilisaurus was most likely an herbivore or omnivore that browsed low vegetation and used speed and agility to evade predators. Because reasonably complete skeletons are known, it provides valuable information on early ornithischian limb proportions, posture and locomotor capabilities. These data contribute to understanding the evolutionary steps toward larger, more specialized ornithopods.
Distinguishing notes
Notable facts include the genus name meaning and the relative completeness of some specimens found in Sichuan, which remain important reference material in collections and publications. For location-specific details refer to regional studies and museum records from Sichuan.