The famous Confuciusornis sanctus fossil from China's northeast Liaoning Province contains patches that appear to be residue from the bird's original tissues. Long evolutionary ages should have made this impossible, since any such biological material would have completely decayed into the tiniest of its constituent chemicals millions of years ago.

A Cambrian rock layer is considered to be "Cambrian" because of the particular fossils it contains. But what does it mean when a rock layer designated as "Ordovician" contains distinctly Cambrian fossils? Paleontologists are facing that question after a recent find in North Africa.

According to evolution, dinosaurs lived during an age when birds and non-reptile land creatures were either present in just a few "primitive" forms or not at all. But a recent National Geographic online interview offered a summary of fossil discoveries made in a dinosaur-bearing deposit in Madagascar.

A piece of oxygen-darkened amber was said to hold a particular arachnid, but it wasn't clearly visible. Scientists made a surprising discovery when a computed tomography scan was able to produce a finely detailed three-dimensional image of a hunting spider. But if the amber is actually 49 million years old, as is claimed, why hadn't it completely darkened long ago?

A massive fossilized spider has set a new size record. It looks like today's golden orb-weavers, which are large enough to dine on small birds. This discovery, in conjunction with similar ones, presents problems for evolutionary origins, and also shows how a name choice can be misleading. What did scientists decide to name this fossil, and why?