Relative dating puts geologic events in chronological ... if an unidentified fossil is found in the same rock layer as an index fossil, the two species must have existed during the same period ...

Researchers have dated volcanic layers at six fossil-bearing sites in Turkey, including one known as Taşhan (shown). The ...

Even the Greeks and Romans realized that layers of sediment in rock signified old age ... Using this technique, called radiometric dating, scientists are able to "see" back in time.

Scientists have discovered the oldest known cerapodan dinosaur fossil in Morocco, discovered back 168 million years.

Relative dating puts geologic events in chronological ... if an unidentified fossil is found in the same rock layer as an index fossil, the two species must have existed during the same period ...