Usually index fossils are fossil organisms that are common, easily identified, and found across a large area. Because they are often rare, primate fossils are not usually good index fossils.

Mysterious fossils can be used to tell time in the deep past. For decades, one of the most abundant kinds of fossils on Earth, numbering in the millions of specimens, was a mystery to paleontologists.

Lt. Col. Thomas James Birch, an avid fossil collector, acquired the fossil from Anning and sold it to the Royal College of Surgeons in London in 1820, with the hopes of raising money for Anning ...

Fossil evidence indicates they had sharp, beaklike jaws to snare prey such as plankton, crustaceans, and other ammonites. They were also preyed on by larger reptiles and fish. Evolution and extinction ...

A creature that scuttled along the seafloor 450 million years ago has been preserved in a rare and striking fossil that formed in fool’s gold.

The 125 million-year-old fossil, found in China’s Liaoning province, shows the skeletons of a prehistoric badgerlike mammal attacking a larger dinosaur called Psittacosaurus.