A portion of a fossilized dinosaur upper arm bone from Tanzania, originally collected in the 1930s, spent many years nestled among thousands of dinosaur specimens housed at London's Natural History Museum. Re-examined, researchers now claim that it is the oldest dinosaur—or almost a dinosaur—in the world.

Well, was it a dinosaur or not?

Gall mites are too small to see without aid, but scientists found two of them after scanning 70,000 amber droplets from Triassic beds in Italy. How much have mites evolved in the supposed 230 million years since they were entombed in amber?

The area surrounding what is now Wuda, Inner Mongolia, once teemed with tropical plants before a tremendous ancient volcanic explosion overwhelmed it. The ash-entombed forest, buried between coal layers, left such remarkably preserved fossilized plants that artists and paleontologists have been able to reconstruct the former wet-forest landscape.

Howell Thomas, senior paleontological preparator for the Natural History Museum of Los Angeles County, was skeptical when a woman claimed that she found a fossilized whale brain in San Luis Obispo County, California, nine years ago.

The evolutionary history of certain extinct marine reptiles just got rewritten.