Kerberosaurus

The True Identity of the “Hell’s Watchdog”: Scary Name, Gentle Herbivore

A 9-meter Duck-billed Dinosaur

Kerberosaurus was a large plant-eating dinosaur reaching a total length of about 9 meters.
Classified within the “Hadrosauridae,” or duck-billed dinosaurs, it efficiently ate plants using its flat beak.
Currently, only cranial fossils have been discovered.

Why “Kerberos”?

While there are various theories, it is said to imply that as they lived at the very end of the Cretaceous, they were the guardians standing at the entrance to the “hellish era” of dinosaur extinction.
While the name evokes a ferocious monster, it was actually an important herbivore supporting the ecosystem just before the extinction event.

From North America to Asia! A “Traveler” Crossing Continents

The most important keyword when discussing Kerberosaurus is “intercontinental migration.”

Connected Continents

Fossil research indicates that Kerberosaurus was a descendant of a group originating in North America.
At that time, Asia and North America were connected by land (such as the Bering Land Bridge).
Their ancestors evolved in North America and were “travelers” who subsequently crossed overland to the Eurasian continent (Russia and East Asia).
This discovery is considered one of the definitive pieces of evidence showing that evolved hadrosaurs advanced from North America into Asia.

Shifting Classification: A Relative of Kamuysaurus (Mukawaryu)?

Kerberosaurus is also a dinosaur whose classification has been subject to changing views.

Early Classification: Saurolophini

Initially, it was thought to belong to the “Saurolophini,” possessing somewhat primitive characteristics similar to “Prosaurolophus” from North America about 75 million years ago.

Recent Classification: Edmontosaurini

However, recent studies increasingly classify it within the “Edmontosaurus tribe” (Edmontosaurini), to which North America’s “Edmontosaurus” and “Kamuysaurus (Mukawaryu)” discovered in Hokkaido, Japan, belong.

According to this new theory, Kerberosaurus would be a close relative of Kamuysaurus.
A grand drama emerges where a group born in North America crossed to Asia, with each lineage undergoing unique evolution in different regions.

Coexistence on the Banks of the Amur River

Kerberosaurus was discovered in the “Tsagayan Formation” in Russia.
This location was once the floodplain of the Amur River.

Another dinosaur from the same Hadrosauridae family, named “Amurosaurus,” has also been found here.
Amurosaurus was a type with a crest on its head (Lambeosaurinae), making it look significantly different from the crestless Kerberosaurus.
In the twilight of the dinosaur era, the “Hell’s Watchdog” and the “Crested Dragon” likely coexisted on the Russian plains, quietly grazing on plants.