Iguanacolossus

What it was like

Iguanacolossus was a large, heavily built relative of Iguanodon, a plant eater that probably walked on all fours much of the time. It is known from a partial skeleton of one animal.

Its world

It lived about 139 to 133 million years ago, in the Early Cretaceous, in what is now Utah. Its bones come from the Cedar Mountain Formation, whose lower layers also held the long-clawed Falcarius.

How it was found

McDonald and colleagues named it in 2010, at the same time as its smaller relative Hippodraco.