The Fukuisaurus was a genus of hadrosaurid ornithopod dinosaurs from the Upper Cretaceous Period of what is now Japan. It was a small to medium-sized herbivore that was closely related to the Iguanodon. However, unlike newer hadrosaurids, the Fukuisaurus had a more primitive form and a fixed mandible that did not support the side-to-side movement of the jaws.

Key Facts

Fukuisaurus pronunciationFoo-kwee-sore-us
What does Fukuisaurus mean?Fukui Lizard
Dinosaur typeOrnithopod
On the menuHerbivorous
Length14.7 feet (4.5 meters)
Height7.5 feet (2.3 meters)
Weight1100 lb (500 kg)
Life expectancyUnknown
Legs used to get aroundQuadruped
Estimated top speedUnknown
When they livedUpper Cretaceous, 122-99 million years ago
Where they have been found?Japan

When & Where

In 1989, Japanese scientists digging in the Kitadani Formation near Fukui City unearthed some fossilized bones that would prove to be from a new genus and species of dinosaur. They would name this new find the Fukuisaurus in 2003, after the city in which it was discovered.

The Kitadani Formation is a sedimentary rock formation that dates back to the Late Cretaceous Period, around 122–99 million years ago. It is located in the Kitadani area of Fukui City, in Fukui Prefecture, on the island of Honshu in central Japan.

The Fukuisaurus is the only genus of dinosaurs to have been found in the Kitadani Formation. However, other fossils from this formation include those of crocodiles, turtles, fishes, pterosaurs, and plants.

Size & Weight

The Fukuisaurus was a small to medium-sized dinosaur. It was approximately 14.7 feet long and 7.5 feet tall at the hip and estimated to have weighed around 1100 lbs.

Mobility & Diet

The Fukuisaurus was a quadrupedal dinosaur, which got around on four legs. It is not known how fast this dinosaur could run, but it was likely similar to other hadrosaurids of its size.

The Fukuisaurus was a herbivore, meaning that it fed on plants. As an iguanodont, it likely fed on grass and low-lying shrubs.

Interesting Points

  • As a herbivore, the Fukuisaurus probably lived in herds for protection from predators.
  • The Fukuisaurus had cheeks built into its jaws that allowed it to store food for later.
  • The Fukuisaurus is generally named an iguanodont, but its posterolateral sternum process is more similar to that of Styracosterna.
  • The Fukuisaurus was a basal hadrosaurid, meaning it was more primitive than other members of its group.

Featured Image Credit: National History Museum