Which statement explains why ammonites are a good example of an index fossil? (1 point)
O Ammonites existed for a relatively limited period of time.
O Ammonites existed long before the dinosaurs
O Ammonites existed in a small geographic area
O Ammonites existed only in the oceans
Ammonites existed for a relatively limited period of time.
The correct statement that explains why ammonites are a good example of an index fossil is:
- Ammonites existed for a relatively limited period of time.
The statement that explains why ammonites are a good example of an index fossil is: "Ammonites existed for a relatively limited period of time."
To understand why ammonites are considered good index fossils, it is important to first understand what an index fossil is. An index fossil is a fossil that is found in a widespread geographic range and is believed to have lived for a relatively short period of time. Index fossils are useful for determining the relative age of rock layers and correlating them across different locations.
Ammonites, which are extinct marine mollusks, existed during the Mesozoic Era, particularly during the Jurassic and Cretaceous periods. During this time, they were abundant and had a wide geographic distribution, living in oceans around the world. However, ammonites became extinct at the end of the Cretaceous period, around 66 million years ago.
Because ammonites lived for a relatively limited period of time and were widespread geographically, their fossils can be used as valuable indicators of the age of rock layers. Finding ammonite fossils in a particular layer of rock helps scientists determine the relative age of that layer and correlate it with other rock layers of similar age in different locations.
Therefore, the statement "Ammonites existed for a relatively limited period of time" explains why ammonites are a good example of an index fossil.