Scientists have discovered two new species of dinosaur, including a "bizarre" creature which was vegetarian although it was related to the giant meat-eater Tyrannosaurus rex.
The dinosaurs were unearthed at a fossil site in the New Mexico desert, which 90 million years ago resembled a swampy forest.
Both animals possessed
features similar to present-day birds, suggesting that they may have been covered in primitive feathers.
One of the dinosaurs is the sloth-like Nothronychus which is a member of the carnivorous group of theropod dinosaurs. Nothronychus, however, had apparently evolved to live on a diet of vegetation.
It weighed about 900kg, measured between 4 and 6 metres long and stood around 3m tall, said Tom Holtz, a palaeontologist from the University of Maryland who took part in the excavations.
The second dinosaur, which has not as yet been named, was a small carnivore measuring 2m long and 1m tall from the coelurosaur family. It probably lived on smaller animals such as lizards and mammals but may have scavanged from much larger corpses. Scientists said it was probably the "coyote of the Cretaceous period".
Nothronychus walked upright on two legs, had a long neck, long arms, dextrous hands and 10cm curved claws on its fingers. It had a large stomach for digesting plant food and its small head was equipped with leaf-shaped teeth designed for shredding vegetation. The dinosaur, described as "truly, truly bizarre" by its discoverers, had a relatively short tail and stood on two stout hind legs.
Nothronychus, which means "sloth-like claw", resembled the giant sloths that roamed prehistoric America many millions of years after the dinosaurs had died out 65 million years ago.
"This opens a window on a time period that otherwise we wouldn't know about," said Dr Holtz, who carried out the work in the Zuni Basin of New Mexico with colleagues Jim Kirkland and Doug Wolfe.
- INDEPENDENT
