Guanlong

The Dinosaur Named “Five-Colored Crowned Dragon”: A Slender yet Ferocious Hunter

Origin and Impact of the Name

The scientific name “Guanlong” comes from the Chinese term “Five-Colored Crowned Dragon” (Wǔ Cǎi Guān Lóng), meaning “Dragon with a Five-Colored Crest.”
This name honors the colorful rock formation (Wucaiwan, or Five Color Bay) where the fossils were found, as well as the distinctive ornamentation on its head.

Minimalist Body and Powerful Jaws

With a body length of about 3 meters and weight of about 100 kg, it was miniature compared to the later Tyrannosaurus, and its body is believed to have been covered in primitive feathers.
However, its mouth was equipped with “premaxillary teeth with a D-shaped cross-section,” a characteristic unique to tyrannosauroids.
This shape is suitable for crushing not just meat but also bone, indicating that despite their small size, they were powerful predators.

Arms with Three Fingers

Also, a decisive difference from Tyrannosaurus is its “arms.”
While they would atrophy to two fingers in later eras, Guanlong’s arms were long and developed, and they had “three” fingers.
They were well-balanced hunters that used both their jaws and arms to hunt.

Functions and Mysteries Hidden in the Head “Crest”

A Fragile and Beautiful Display

Its most distinctive feature, the huge crest on its head, reached about 6 cm in height but was extremely thin and hollow (air-filled structure).
Therefore, it was useless as a weapon and was so delicate that it would be irreparable if broken once.

Why Was Such a Cumbersome Ornament Necessary?

Currently, the following two theories are dominant:

Display (Courtship/Identification)

Like a peacock’s feathers, a billboard to appeal strength to the opposite sex or recognize peers.

Handicap Hypothesis

Evolution to prove “I am strong enough to survive even with such a fragile and conspicuous ornament.”

Comparison of fossils shows the crest grew larger with age, so it seems to have functioned as proof of “transformation” into adulthood.

The Lineage of Emperors Began in Asia

A Discovery Filling a 30-Million-Year Gap

The 2005 discovery determined that the origin of tyrannosauroids lies in “Asia.”
Guanlong from the Late Jurassic (about 160 million years ago) is important evidence showing that the roots of the giant North American emperors actually lay in small Asian dinosaurs.

A Long-Lasting Bloodline

Taxonomically belonging to the “Proceratosauridae,” it was a distinguished bloodline that survived for a long time alongside relatives like the feathered dinosaur Yutyrannus and Dilong.
Here lies the drama of evolution, leading from small, feathered ancestors to the giant Tyrannosaurus over 90 million years.

The Tragedy of the Mud Trap and the Truth Told by Bones

The two full skeletons discovered were found in a situation akin to a suspense drama.

The Trap of Giant Footprints

They were found inside a depression formed by the fossilized footprint of a giant sauropod (Mamenchisaurus species).
At the time, filled with clay mixed with volcanic ash, it had become a pitfall like a “bottomless swamp.”

Chain of Death and Cannibalism

In this mud pit, small theropods like Limusaurus fell victim first, and the Guanlong attracted by their carcasses also got stuck in the mud and perished.
Even more shockingly, there are traces of the adult Guanlong attacking the sub-adult (young individual) that fell in with it, suggesting “cannibalism” occurred in this extreme situation.

Lifespan Revealed by Bone Rings

Analysis of the bones revealed the adult died at age 12 and the sub-adult at age 6.
Their lifespan was shorter compared to the later Tyrannosaurus, suggesting they matured early and lived harsh, short lives.