| Diet | Omnivore |
| Height | 0.25m |
| Length | 0.75m |
| Weight | 760 g |
| Environment | Land |
| Era | Cretaceous |
| Period | Late Cretaceous |
| Type | Theropod |
| Location | Mongolia |
Ceratonykus was a tiny theropod dinosaur that lived approximately 83.6 million years ago during the Late Cretaceous period in what is now Mongolia. Despite its diminutive size of just 75 centimetres long and weighing only 760 grams—roughly the size of a large crow—this fascinating creature was a highly specialised hunter with remarkable adaptations.
Living in the ancient landscapes preserved in the Barun Goyot Formation, Ceratonykus inhabited a semi-arid environment of sand dunes and occasional lakes. Its most distinctive feature was its powerful, clawed forelimbs, which gave the dinosaur its name meaning 'horny claw'. These robust arms were likely used for digging into termite mounds and ant colonies, making Ceratonykus a specialised insectivore, though it probably also ate small vertebrates and plant matter when available.
Known from fragmentary remains including an incomplete skull, Ceratonykus represents one of the smallest dinosaurs ever discovered. Its large eye sockets suggest it may have been active during twilight hours, using keen eyesight to hunt for prey. The discovery caused scientific debate, with its original describers controversially suggesting it might be an ornithischian rather than a theropod, though this classification has not been widely accepted.
Some palaeontologists consider Ceratonykus may actually be the same species as another tiny Mongolian dinosaur called Parvicursor, which would make it a junior synonym. However, until more complete fossils are found, Ceratonykus remains a valid but mysterious member of the diverse theropod family tree.
Ceratonykus was distinguished by its extremely small size, robust clawed forelimbs adapted for digging, and proportionally large eye sockets. Its powerful arms contrasted sharply with its tiny overall body size, suggesting highly specialised feeding behaviour.
Ceratonykus likely spent much of its time digging into insect colonies with its powerful claws, possibly feeding during dawn and dusk hours when its large eyes would have been most advantageous. It probably moved quickly across the ground on its long hind legs, darting between feeding sites in its semi-arid habitat.
| Phylum | Chordata |
| Class | Saurischia |
| Order | Avetheropoda |
| Genus | Ceratonykus |
Ceratonykus was first described by Vladimir Alifanov and Rinchen Barsbold in 2009. The original fossils were discovered at Barun Goyot Formation, Mongolia.
