Duonychus

What it was like

Duonychus was a therizinosaur, a pot-bellied plant eater with a long neck and big claws. Unlike its relatives, which had three fingers, Duonychus had only two fingers on each hand, each tipped with a large, curved claw.

One of its claws still has its horny sheath preserved, which shows that the claw in life was even longer than the bone inside. It may have used its hands to pull branches toward its mouth.

Its world

It lived in the Late Cretaceous in what is now Mongolia. Its fossil comes from the Baynshire Formation, where it shared the land with other therizinosaurs, Segnosaurus and Erlikosaurus, the raptor Achillobator and the armored Talarurus.

How it was found

Kobayashi and colleagues named Duonychus in 2025, from a single partial skeleton.