index fossil
Plural
index fossils
1
a fossilized organism that is useful for dating and correlating the strata in which it is found, typically indicative of a particular time period in Earth's geological history
- The trilobite is an index fossil commonly used to date Paleozoic rock layers.
- Geologists rely on index fossils to determine the relative age of sedimentary rock formations.
- The presence of ammonite shells in a layer serves as an index fossil for the Jurassic period.
- Index fossils help establish the geological timeline and the sequence of events in Earth's history.
- Studying index fossils aids in understanding evolutionary patterns and ancient ecosystems.
Synonyms: