Most scientists have believed for years that the extinction of the dinosaurs was caused by a meteorite strike off the coast of Mexico’s Yucatan Peninsula. The Chicxulub Crater is evidence that a meteor struck just off the coast, but Princeton University scientists recently refuted the theory that this meteor was responsible for the demise of dinosaurs because it struck 300,000 years before dinosaur extinction.

A nearly complete fossil of what is now known as a Raptorex was discovered in Northern China. This small-scale Tyrannosaurus rex lived long before the well known T-Rex and weighed about the same as a human. Paleontologists note that the Raptorex was about nine feet long and weighed only 150 pounds. It lived 125 million years ago, about 35 million years before giant Tyrannosaurs roamed the earth.

On the heels of his discovery in Montana of the first trace fossil of a dinosaur burrow, Emory University paleontologist Anthony Martin has found evidence of more dinosaur burrows – this time on the other side of the world, in Victoria, Australia. The find suggests that burrowing behaviors were shared by dinosaurs of different species, in different hemispheres, and spanned millions of years during the Cretaceous Period, when some dinosaurs lived in polar environments.

For millions of years, dinosaurs have been considered the largest creatures ever to walk on land. While they still maintain this status, a new study suggests that some dinosaurs may actually have weighed as little as half as much as previously thought.

Researchers from the Teruel-Dinópolis Joint Palaeontology Foundation have compared an Allosauroidea tooth found in deposits in Riodeva, Teruel, with other similar samples. The palaeontologists have concluded that this is the largest tooth of a carnivorous dinosaur to have been found to date in Spain.

The discovery of a gruesome feeding frenzy that played out 73 million years ago in northwestern Alberta may also lead to the discovery of new dinosaur species in northwestern Alberta.

The enduringly popular theory that the Chicxulub crater holds the clue to the demise of the dinosaurs, along with some 65 percent of all species 65 million years ago, is challenged in a paper to be published in the Journal of the Geological Society on April 27, 2009.

During the last 540 million years, the earth's oxygen levels have fluctuated wildly. Knowing that the dinosaurs appeared around the time when oxygen levels were at their lowest at 12%, Tomasz Owerkowicz, Ruth Elsey and James Hicks wondered how these monsters coped at such low oxygen levels.

A herd of young birdlike dinosaurs met their death on the muddy margins of a lake some 90 million years ago, according to a team of Chinese and American paleontologists that excavated the site in the Gobi Desert in western Inner Mongolia.

Evolutionary biologists use two ways to study the evolution of prehistoric plants and animals: firstly they use radioactive dating techniques to put fossils in chronological order according to the age of the rocks in which they are found (stratigraphy); secondly they observe and classify the characteristics of fossilised remains according to their relatedness (morphology).

The official State Dinosaur of Texas is up for a new name, based on Southern Methodist University research that proved the titleholder has been misidentified.

Fossil showing Epidexipteryx, the pigeon-sized feathered dinosaur that lived 168-152 million years ago. Its long tail feathers, shown at bottom right, were most likely used for display. Fucheng Zhang