Fukuisaurus

Fukuisaurus was an herbivorous dinosaur that lived in what is now Japan during the Early Cretaceous, around 120 million years ago. Known from skull elements and partial skeletal remains found in the Kitadani quarry near Katsuyama, it was an early hadrosauroid related to the duck-billed dinosaurs. Measuring approximately four and a half metres in length, it was a modestly sized animal capable of walking on all fours while browsing or rearing onto two legs to run or reach taller foliage. Its skull possessed closely packed teeth ideal for grinding tough vegetation, although its upper jaw was more rigid than that of later duck-billed relatives. Fukuisaurus shared its forested habitat with the meat-eating Fukuiraptor and sauropods like Fukuititan, playing a key ecological role as an efficient, medium-sized consumer of ferns, cycads, and conifers.

Unlike advanced hadrosaurids, its upper jaw bones were solidly fused, preventing side-to-side chewing movements.

Where and when

Fukuisaurus lived in the Early Cretaceous, from 121.4 to 113 million years ago (Aptian age). Its remains come from Japan, in the Kitadani Formation.

The numbers

Length 4.8 m (estimates run from 4.5 to 5 m). Mass about 490 kg. Hip height about 1.5 m. That is 2.8 human-lengths, or 0.43 of a double-decker bus. These are estimates from partial skeleton; fields marked estimated by the site are length, mass, first ma, last ma, hip height.

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