Two species of 鈥渂izarre鈥� bird-like dinosaurs that lived 90 million years ago have been unearthed in New Mexico.
Very few dinosaur fossils from this period have been found. 鈥淭his opens a window on a time period that otherwise we wouldn鈥檛 know about,鈥� said Tom Holtz, a palaeontologist at the University of Maryland, who was involved in the excavations.
The team discovered a vegetarian sloth-like dinosaur with a beaked head, called Nothronychus. It is a therapod, as is Tyrannosaurus rex, but it did not share its cousin鈥檚 taste for flesh. Giant pandas are modern examples of herbivores evolved from carnivorous ancestors.
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Nothronychus, which would have walked mostly upright, weighed about one tonne and stood three to 3.5 metres tall, say the team. It probably used its long arms to pull down branches to reach leaves.
The other find is an as yet unnamed member of the coelurosaur family. This coelurosaur was similar in body shape to T. rex, but only about a metre tall. It probably ate lizards and small mammals.
The two fossil skeletons were found less than a kilometre apart, close to New Mexico鈥檚 border with Arizona, in an area called the Zuni Basin.
Although the paleontologists found no evidence of fossilised feathers, similar skeletons unearthed in China and Mongolia are thought to have been feathered. Holtz speculates that the coelurosaur probably had a shaggy, feathery coat.
鈥淭hey are truly, truly bizarre,鈥� said co-researcher Doug Wolfe.