0 a fossil that is found in many places and comes from the same time in history, so that scientists can use it to decide how old certain rocks are
1 a fossil that is found in many places and comes from the same time in history, so that scientists can use it to decide how old certain rocks are
It has a cosmopolitan distribution and is an important index fossil in biostratigraphy.
It is used in biostratigraphy as an index fossil.
The series of deposits that spans the occurrence of a particular index fossil, is often referred to as that fossil's zone, enabling to relate different faunas through time.
Firstly, index fossils should be temporally restricted, numerically abundant and spatially widespread.
Apart from conodonts, goniatites are the best index fossils, which have considerably completed the biostratigraphic calibration of our sections.
An absence of facies bias potentially increases the usefulness of these taxa as index fossils, but their global utility is restricted by their endemism (see above).
Because certain fossils are solely found in certain layers, they are referred to as index fossils.
Such index fossils must be distinctive, be globally distributed and have a short time range to be useful.