Guanlong

The Dinosaur Named “Five-Colored Crown Dragon”: A Slender but Ferocious Hunter

The Origin of Its Name and Its Impact

The scientific name “Guanlong” is derived from the Chinese words “Wucai Guanlong,” which translates to “crown dragon of five colors.”
This name pays homage to the vibrant colors of the rock formation where its fossils were discovered (Wucaiwan) and the characteristic ornamental crest on its head.

A Minimal Body with Powerful Jaws

With a body length of about 3 meters (9.8 feet) and a weight of about 100 kg (220 lbs), it was miniature in size compared to the later Tyrannosaurus, and it is believed its body was covered in primitive feathers.
However, its mouth was equipped with “front teeth with D-shaped cross-sections,” a defining characteristic of tyrannosaurs.
This shape was well-suited for crushing not just meat but also bone, indicating that despite their small size, they were powerful predators.

Arms with Three Fingers

Another crucial difference from Tyrannosaurus was its “arms.”
While these arms would degenerate to have only two fingers in later eras, Guanlong’s arms were long and well-developed, complete with “three” fingers.
They were well-balanced hunters that used both their jaws and their arms to catch their prey.

The Functions and Mysteries Hidden in the “Crown” (Crest) Atop Its Head

A Fragile and Beautiful Display

Its most striking feature, the massive crest on its head, reached a height of about 6 cm (2.4 inches) but was extremely thin and hollow (filled with air).
Therefore, it was useless as a weapon and was so delicate that it would likely have been irreparable once broken.

Why Was Such a Cumbersome Ornament Necessary?

Currently, the following two theories are the most prominent:

Display (Courtship and Recognition)

Like the feathers of a peacock, it served as a billboard to flaunt its strength to the opposite sex or to visually recognize members of its own species.

The Handicap Principle

An evolutionary adaptation to prove, “I am so strong that I can survive even with such a fragile and conspicuous ornament.”

Comparisons of fossils reveal that the crest grew larger as the dinosaur matured, suggesting it functioned as physical proof of “transformation” into an adult.

The Emperor’s Lineage Began in Asia

A Discovery Filling a 30-Million-Year Gap

Its discovery in 2005 definitively proved that the origins of tyrannosaurs lay in “Asia.”
Guanlong, from the Late Jurassic (about 160 million years ago), is a vital piece of evidence showing that the roots of the giant emperors of North America actually trace back to small dinosaurs in Asia.

A Long-Lasting Bloodline

Taxonomically, it belongs to the “Proceratosauridae” family. It was a distinguished bloodline that survived across many epochs alongside relatives like the feathered dinosaurs Yutyrannus and Dilong.
Herein lies the evolutionary drama of how a small, feathered ancestor transformed into the massive Tyrannosaurus over the course of 90 million years.

A Muddy Tragedy and the Truth Told by Bones

The two fully articulated skeletons were discovered in a situation resembling a suspense drama.

The Trap of a Giant Footprint

They were found inside a fossilized depression created by the footprint of a massive sauropod (a mamenchisaurid).
At the time, this footprint had become a “death trap” resembling a bottomless pit, filled with a mixture of volcanic ash and mud.

A Chain of Death and Cannibalism

In this mud trap, small theropods like Limusaurus fell victim first. Drawn by their carcasses, the Guanlong also got their feet stuck in the mud and perished.
Even more shockingly, there are traces indicating that the adult Guanlong attacked the subadult (youngster) that fell in with it, suggesting the possibility that “cannibalism” took place under extreme survival conditions.

Lifespan Revealed by the “Tree Rings” of Bones

Bone analyses revealed that the adult died at 12 years old, and the subadult died at 6 years old.
Their lifespans were significantly shorter than that of the later Tyrannosaurus, suggesting they led fast-paced, harsh, and brief lives.