Equijubus

An “Intermediate Existence” Standing in the Evolutionary Gap

Taxonomically, Equijubus is considered a type of primitive hadrosaur (duck-billed dinosaur).
However, a close examination of its physical characteristics reveals that it is not merely a duck-billed dinosaur.

Their bodies retain strong characteristics not only of duck-billed dinosaurs but also of the older “Iguanodon” type.
In other words, Equijubus possesses intermediate traits from two different groups: “Iguanodon” and “duck-billed dinosaurs.”
This serves as “living proof” that they were in the midst of evolution, making them indispensable for understanding the evolutionary process of dinosaurs.

A “Face” Like a Duck-billed Dinosaur, “Teeth” Like an Iguanodon

The “intermediate characteristics” of Equijubus are particularly evident in its skull structure.
Their facial features were like a mosaic, a blend of old and new traits.

Evolved Facial Features (Characteristics of Duck-billed Dinosaurs)

First, if we look at external features such as the shape of the “cheeks” and “snout,” they closely resembled those of evolved duck-billed dinosaurs.
Based on these features, there is no doubt that Equijubus belongs to the hadrosaur lineage.
Judging by their faces alone, they had already acquired the appearance of next-generation dinosaurs.

Primitive Mouth Structure (Characteristics of Iguanodontia)

However, remnants of an older era were clearly etched inside their mouths.

The greatest characteristic of evolved duck-billed dinosaurs is the advanced chewing system called the “dental battery,” where countless teeth are densely packed.
Thanks to this, they could efficiently eat tough plants.
However, Equijubus was not equipped with this dental battery.

Tooth Characteristics

The teeth in the upper and lower jaws were roughly the same size.

Structure

Remarkably similar to the teeth of primitive Iguanodontia.

Even though the face shape had evolved, the system for eating plants remained primitive.
It is precisely this imbalance that vividly tells the story of Equijubus being in a transitional period of evolution.

The Drama of Evolution That Occurred in Asia

This characteristic of having a “modern face but primitive teeth” suggests an important fact in dinosaur evolutionary history.

For many years, there has been much debate regarding “when and where” the evolution from Iguanodon to duck-billed dinosaurs occurred.
The fact that a dinosaur with such intermediate characteristics lived in Asia about 110 million years ago supports the high probability that this important evolutionary event took place in “Asia.”

The existence of Equijubus is significant evidence indicating that the transition from Iguanodon to duck-billed dinosaurs originated in the lands of Asia and spread to the world from there.

Origin of the Name “Horse Mane”

Finally, let’s explain the origin of this dinosaur’s slightly unusual name.
The scientific name “Equijubus” means “horse mane” in Latin.

Hearing this name, you might imagine, “Did it have a mane like a horse?” but in reality, their appearance did not resemble a horse.
This name was chosen based on the “Chinese place name” where the fossils were discovered.

• Discovery Site: “Mazongshan” (Horse Mane Mountain) in Gansu Province
• Meaning of Place Name: “Mountain of the Horse Mane”

Named not for its appearance but out of respect for the land of its discovery, the name conveys to this day that this important dinosaur was found on Asian soil.