It must be distinct from other organisms.
It must have lived in a very wide geographic region
Geologists use index fossils to date the rock layers they are found in and to correlate similar rock layers in different locations. Three characteristics of a good index fossil are: widespread distribution, short duration in the geologic time scale, and easily recognizable features.
An index fossil must be of a rapidly evolving organism that only existed for a specific period of time, is easily recognizable, is abundantly preserved, and was widespread geographically. Most index fossils are therefore of marine organisms.
This is called an index fossil.
To be an index fossil, it must be widespread, commonly found (sometimes in groups) and have a short life span for which it lived. If a fossil meets all three of these requirements, it is considered an index fossil.
C). a narrow time range and a wide geographic range
They are called index fossils.
The absolute age of the index fossil was determine by radioactive dating or another absolute method
hiii
An index fossil. An index fossil's age is known, allowing scientists to know the relative age of other fossils based on their position relative to the index fossil. (Ex. If a fossil is deeper in the earth, it is older than the index fossil)
The relative age of a fossil that can be determined by comparing it to an index fossil is called biostratigraphic dating. This method relies on the known age range of the index fossil to estimate the relative age of the fossil being studied.
Index Fossil
To be useful as an index fossil fuel, spices must have existed for about 1000 years.