BBC June, 2001, 16:42 GMT 17:42 UK

More feathered dinosaurs found

Scientists in America claim to have discovered two new "bird-like" species of feathered dinosaur, unearthed in New Mexico.

The two dinosaurs - the sloth-like Nothronychus and a small carnivore from the coelurosaur family that has not yet been named - lived 90 million years ago in swampy forests.

At that time - the middle of the Cretaceous period of the Mesozoic era - Earth was in the throes of extreme global warming that melted the polar ice caps and dramatically reduced the land area on the planet.

Very few dinosaur fossils dating from this period have so far been found.

"This opens a window on a time period that otherwise we wouldn't know about," said University of Maryland paleontologist Tom Holtz.

Nothronychus (pronounced "no-thron-EYE-kus") is a member of the theropod class of meat-eating dinosaurs that includes Tyrannosaurus and Allosaurus, but it apparently evolved into a plant-eater, said Jim Kirkland, a paleontologist with the Utah Geological Survey.

The creature weighed about a tonne, was 15 to 20 feet (4.5 to 6 metres) long and stood 10 to 12 feet (3 to 3.6 metres) tall, he said.

Plant-eater

It had two legs and walked more upright than its meat-eating cousins, had a long, thin neck, long arms, dexterous hands, four-inch (10-cm) curved claws on its fingers, a large abdomen, a small head with a mouth full of leaf-shaped teeth designed for shredding vegetation, a relatively short tail and stout back legs, the scientists said.

"They are truly, truly bizarre," added paleontologist Doug Wolfe, director of the Zuni Basin Paleontological Project.

It is the first example of a group of dinosaurs called therizinosaurs to be found in the Americas. The others all came from China and Mongolia.

No fossil evidence was found of feathers, but Wolfe noted that similar dinosaurs from Asia were found with feathers and speculated that this one had "a loose gaggle of feathers around the head and along the spine, back of the arms and legs".

-- Anonymous, June 19, 2001

Answers

What would feathers do for such a creature?

-- Anonymous, June 19, 2001

Peter, feathers provide superior insulation. Oily, they repel water. However, the modern feather structure is so complex and so related to flight (well, the "flight" feathers, at least), that it's beyond me to understand how they could have evolved.

-- Anonymous, June 19, 2001