Found: the trend-setting dinosaur that went veggie

It walked on two legs, looked like an ostrich, had hands the size of a gorilla's and lived 125 million years ago - meet the latest dinosaur discovery.

Fossilised bones of the feathered, bird-like creature, Falcarius utahensis, were unearthed at a remote mountain site in the western US state of Utah. The palaeontologists who discovered the creature said yesterday it had evolved from a carnivore and was well on the way to becoming a plant-loving herbivore.

James Kirkland, a palaeontologist at the Utah Geological Survey, said: "[It] shows the beginning of features we associate with plant-eating dinosaurs, including a reduction in size of meat-cutting teeth to leaf-shredding teeth, the expansion of the gut to a size needed to ferment plants, and the early stages of changing the legs so they could carry a bulky body instead of running after prey."

It is not known exactly what Falcarius utahensis ate. It might still have lived on meat but, according to a study in the journal Nature, it almost certainly ate plants.

Falcarius - which is Latin for sickle-maker - had sickle-shaped claws up to 10cm long on its feet and forelimbs, and was about 1.5m tall and 4m long. It is related to the fearsome velociraptors, the two-legged carnivores shown in the film Jurassic Park, and to a plant-eating group of dinosaurs called the therizinosaurs.

Scott Sampson, chief curator of the Utah Museum of Natural History, said: "With Falcarius, we have actual fossil evidence of a major dietary shift, certainly the best example documented among dinosaurs. This little beast is a missing link between small-bodied predatory dinosaurs and the highly specialised and bizarre plant-eating therizinosaurs."

The palaeontologists have found nearly 2,000 bones at the Utah siteover the past three years. One theory suggests the area was a watering hole and that animals visiting it were either poisoned or gassed by vapours from a spring at least twice.

The scientists were led there by a man convicted of taking fossils without a licence. "We never would have found it, at least for a 100 years or so, if he hadn't taken us to the site," said Professor Kirkland.

"Once he figured out he had a new dinosaur, he realised scientists should be working the site."