use the image below. Which fossil is a good example of an index fossil? (1 point)
Trilobite because it only appears in one layer (limited time) and in one column (single area).
Gastropod because it appears in multiple layers (long period of time) and in 3 columns (multiple areas) Gastropod because it appears in multiple layers (long period of time) and in 3 columns (multiple areas)
Ammonite because it appears in only 1 layer (limited time) but in 3 columns (multiple areas)
Trilobite because it only appears in one layer (limited time) and in one column (single area).
The fossil that is a good example of an index fossil is the Trilobite because it only appears in one layer (limited time) and in one column (single area).
To determine which fossil is a good example of an index fossil, we need to consider the definition of an index fossil and the characteristics of the fossils mentioned.
An index fossil is a species that lived for a relatively short period of time and had a wide geographic distribution. It serves as a useful tool in determining the relative age of rock layers in different areas.
Let's assess the information provided for each fossil:
1. Trilobite:
- Appearance: It only appears in one layer (limited time) and in one column (single area).
- Conclusion: While it is limited in both time and area, it does not meet the criteria of having a wide geographic distribution, which is an important characteristic of an index fossil.
2. Gastropod:
- Appearance: It appears in multiple layers (long period of time) and in three columns (multiple areas).
- Conclusion: The gastropod fossil meets the criteria of having a wide geographic distribution and being present in multiple layers over a long period of time. This makes it a good candidate for an index fossil.
3. Ammonite:
- Appearance: It appears in only one layer (limited time) but in three columns (multiple areas).
- Conclusion: While the ammonite fossil is present in multiple areas, its limited time of appearance does not fully meet the criteria of an index fossil, as it should have a relatively short period of existence.
Based on the information provided, the fossil that best exemplifies an index fossil is the Gastropod. It appears in multiple layers (long period of time) and in three columns (multiple areas), indicating both a wide geographic distribution and a relatively long span of existence.