The giant dinosaurs that roamed the world some 150 million years ago shared the planet with equally daunting parasites: blood-gobbling fleas that were up two centimeters long.

So say Chinese and French paleontologists, who have pored over nine extraordinary fossils unearthed from Inner Mongolia and Liaoning province.

Contrary to its alluring name, Venus is the planet from hell, with an atmosphere so hot, toxic and heavy that any visitor would risk being simultaneously melted, suffocated and crushed.

But not just that: the second planet from the Sun turns on its axis so slowly that, for any survivor, a Venusian day would seem interminable, for it is the equivalent of 243 days on Earth.

A major river in India's northeast that originates in Tibet has suddenly dried up, triggering speculation that China might be responsible, a local official told Agence France Presse on Thursday.

The Brahmaputra has its source in China's southwestern Tibet region where it is known as the Yarlung Tsangpo, and it enters India in the mountainous, remote northeastern state of Arunachal Pradesh, where it is called the Siang.

To save the imperiled spotted owl, the Obama administration is moving forward with a controversial plan to shoot barred owls, a rival bird that has shoved its smaller cousin aside.

The plan is the latest federal attempt to protect the northern spotted owl, the passive, one-pound bird that sparked an epic battle over logging in the Pacific Northwest two decades ago.

Nepal is appealing to international donors to help it finally settle a long-running dispute over the height of Mount Everest, a government official said Wednesday.

The world's highest peak, which straddles Nepal and China, is usually attributed a height of 8,848 meters (29,029 feet) following an Indian survey in 1954, but other more recent measurements have varied by several meters.

Bottlenose dolphins have whistles which they use to exclusively greet other members of their species, marine biologists in Scotland reported on Wednesday.

Using hydrophones, the researchers made recordings of dolphins swimming in St. Andrews Bay, off the northeastern coast of Scotland, in the summers of 2003 and 2004.

Scientists say they have proof that the Tyrannosaurus rex, the dinosaur adored by children and makers of plastic toys, had the most powerful bite of any creature that lived on land.

The bite of a grown T. rex was up to 10 times that of a Mississippi alligator, exerting a force of nearly six tons -- the weight of an elephant -- on a single tooth, according to a study published on Wednesday.

After two unexpected pregnancies at a sanctuary for retired research chimpanzees, other females have been put on birth control and the males are getting another round of vasectomies.

The first recent pregnancy at the Chimp Haven Inc. facility near Shreveport in northwest Louisiana was discovered on Valentine's Day when a worker noticed Flora, a 29-year-old chimp, was carrying a newborn.

Melting sea ice in the Arctic may be causing the snowier winters the northern hemisphere has experienced in the last two seasons, U.S. and Chinese researchers have reported.

The level of Arctic sea ice reached a new record low in 2007, said the study led by the Georgia Institute of Technology and published in the Proceedings of the National Academy of Sciences on Monday.

A coalition of environment groups called Tuesday for the world's largest marine reserve to be declared in Antarctica's Ross Sea to prevent "industrial scale" fishing ruining the pristine ecosystem.

The Antarctic Ocean Alliance said waters surrounding the remote frozen continent were facing increased exploitation as fish stocks elsewhere in the world continue to decline.