The Yinlong is a genus of herbivorous ceratopsian dinosaurs that lived during the Mid Jurassic period in what is now China. The name Yinlong means “hidden dragon” in Chinese. It was first described in 2006 by Lü Junchang and colleagues from fossils discovered in the Dashanpu Quarry, located in the Shishugou Formation of Xinjiang.

The Yinlong is a small ceratopsian with an estimated length of 1-2 meters (4 ft). Its body is slender and gracile, with long hind limbs and a long tail. The skull is small and delicate, with large eyes and a beaked snout.

Key Facts

Yinlong pronunciationyin-long
What does Yinlong mean?Hidden Dragon
Dinosaur typeCeratopsian
On the menuHerbivorous
Length1.2 meters (4 feet)
Height0.4 m (1 foot 31 inches)
Weight9kg  (about 20 lbs)
Life expectancyUnknown
Legs used to get aroundBiped/Quadruped
Estimated top speedUnknown
When they livedLate Jurassic era 159-154 million years ago
Where they have been found?China

When & Where

In 2004, a group of American and Chinese paleontologists was prospecting for fossils in the Shishugou Formation of Xinjiang, China. They stumbled upon a nearly complete skeleton of a small plant-eating dinosaur, only missing the tip of the tail.

The skull was still attached to the neck, and most bones were in good condition. After further study, they realized it was a new genus and species, which they named Yinlong downsi—”hidden dragon” in Mandarin.

Size & Weight

This little guy was only about 4 feet (1.2 meters) long and weighed less than 20 lbs (9 kg), making it one of the smallest known ceratopsians.

For comparison, the largest ceratopsian, Triceratops, reached lengths of 9 meters (30 ft) and weighed as much as 12 metric tons (13 short tons).

Mobility & Diet

The Yinlong was a small, agile creature, able to move on both two legs and four.

It is thought to have been an opportunistic feeder, eating whatever low-lying plants and shrubs were available.

It had around 30 teeth in its lower jaw, which were long, thin, and curved backwards. The teeth would have been good for slicing plants, but not crushing or grinding them. Seven gastrolites (stomach stones) were found in the stomach region of the Yinlong fossil, which suggests that it may have used these stones to help grind up its food.

Interesting Points

  • The Yinlong had features of different groups of ceratopsians. It had a short, parrot-like beak like Psittacosaurus and gastroliths like Lesothosaurus. But it also had horns on its head, like the better-known Triceratops.
  • The Yinlong is the oldest known member of the Ceratopsia and the only one known from the Jurassic period. All other ceratopsians lived during the Cretaceous period, which began about 145 million years ago.
  • The Yinlong was small in size with a broad snout. It had a relatively long neck and tail and slender legs adapted for running.

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