How do fossils contribute to our understanding of geological time?

Fossils are incredibly valuable in understanding geological time because they represent remnants or traces of once-living organisms. By studying fossils, geologists can infer not only the types of life that existed during different geological periods but also the environments in which these organisms lived. For example, fossilized remains of marine creatures can indicate ancient oceans or seas, while fossils of plants may suggest previous land ecosystems.

Through the identification and dating of different fossilized species, scientists can establish relative ages of rock layers. This layering of fossils can help create a timeline of life on Earth, marking significant events such as mass extinctions or the emergence of new species. Thus, the study of fossils enables a deeper understanding of the biological and environmental changes over geological time, effectively linking the history of Earth’s geologic processes with the evolution of life.