Fossil species that are used to distinguish one layer from another are called index fossils. Index fossils occur for a limited interval of time. Usually index fossils are fossil organisms that are ...

When a species is really abundant, widespread, distinctive, and found in a restricted span of time, their remains can be used as Index Fossils. These are fossils that help geologists correlate and ...

Paleontologist Mary Anning discovered the ichthyosaur fossil in 1818, two decades before the word dinosaur was even part of our lexicon. The ancient marine reptiles got the name ichthyosaur ...

Because some ammonites only lived during specific periods, when geologists find such fossils, they know the age of the ...

Ammonite shells are used today as index fossils, meaning they can help date other fossils that are found in the same layer of marine rock. These cephalopods make for ideal index fossils because ...

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. Ancient plant ...

The discovery comes from a fossil of an ancient firefly species that was initially discovered in 2016, trapped in 99 million-year-old Burmese amber from northern Myanmar. The beetle is only the ...