The Agilisaurus (“agile lizard”) was a small herbivorous ornithischian dinosaur that lived in China during the Middle Jurassic period, approximately 161–168 million years ago. It was a small dinosaur, measuring only about the same size as a human child. The Agilisaurus was a highly agile creature, and its name reflects this fact.

Key Facts

Agilisaurus pronunciationAj-i-li-sore-us
What does Agilisaurus mean?Agile Lizard
Dinosaur typeOrnithopod
On the menuHerbivorous
Length1.2-1.7 meters
Height0.6 meters
Weight40 kg
Life expectancyUnknown
Legs used to get aroundBipedal
Estimated top speedUnknown
When they livedMiddle Jurassic, 161-168 million years ago
Where they have been found?China, Eastern Asia

When & Where

The holotype of the Agilisaurus, which is also the only known specimen, was recovered in 1984 during the construction of the Zigong Dinosaur Museum in Zigong, Sichuan Province, China. The strata from which it was recovered have been dated to the early Oxfordian stage of the Middle Jurassic, approximately 161-168 million years ago.

The genus and species were later described and named in 1990 by Chinese paleontologist Peng Guangzhao. He named the type and only species Agilisaurus louderbacki,  after Dr. George Louderback, who was the first to identify dinosaur fossils in the Sichuan Basin.

Size & Weight

By adult standards, the Agilisaurus was a pretty small dinosaur. It is estimated to have reached lengths of 1.2-1.7 meters (4-5.6 feet) and weighed around 40 kg (88 lbs).

Mobility & Diet

Like other ornithopods, the Agilisaurus was a bipedal (two-legged) dinosaur. It is thought to have been an agile creature, with fossil evidence showing that its tibia (shin bone) was relatively long compared to its femur (thigh bone). This would have given the Agilisaurus an extra spring in its step and helped it to move quickly.

The Agilisaurus was a herbivorous (plant-eating) dinosaur. It had a beak-like structure on its upper and lower jaws, which would have been ideal for stripping leaves off plants. This is a common feature among ornithopods, as it would have helped them to eat a wide variety of plants.

Interesting Points

  • The Agilisaurus is thought to be closely related to the Yandusaurus, another small ornithischian dinosaur that lived in China during the Middle Jurassic.
  • Its leaf-shaped teeth had a wavy enamel pattern, which is thought to have helped it grind up plant food without wearing down its teeth too quickly.
  • The Agilisaurus tailbone lacked the stiffening interwoven bony rods found in the tails of other dinosaurs. For this reason, many scientists believe that it was a burrow-dwelling creature.
  • The Agilisaurus is one of the smallest dinosaurs known from nearly complete fossil remains. It can be found on display at the Zigong Dinosaur Museum in Zigong, China.

Featured Image Credit: ArthurWeasley~commonswiki assumed (based on copyright claims), CC BY-SA 3.0, via Wikimedia Commons