One the most agile dinosaurs so far discovered has been unearthed in China.

The tiny dinosaur, dubbed a "roadrunner" by the scientists who found it, is also one of the smallest dinosaurs known.

Measuring just half a metre long, the fleet-footed theropod named Xixianykus zhangi was likely to have used a huge claw to dig for termites and ants.

It then used its speed to efficiently move between ant mounds and avoid the attentions of larger predators.

Details of the discovery are published in the journal Zootaxa.