What is indicated by the principle of fossil succession in sedimentary strata?

The principle of fossil succession is a fundamental concept in geology that states that fossil organisms follow one another in a definite and recognizable order within sedimentary rock layers. This means that particular types of fossils can be found in the same sequence across different geographic locations, providing a reliable way to date and correlate rock layers.

The correct answer reflects the systematic appearance and extinction of species over geological time; specific fossils characterize particular time periods. For example, if a certain type of fossil is found in one layer and another type is found in a layer above it, it indicates that the latter species evolved after the former was present, thus demonstrating the chronological sequence of life on Earth.

This principle helps geologists understand the relative ages of rock layers and the history of life on Earth, making it a crucial tool for stratigraphy and paleontology. In contrast, the other options don't accurately characterize the essence of fossil succession. For instance, randomness in fossil arrangement would contradict the established order that the principle identifies, and the notion of fossils remaining unchanged does not hold true as evolution leads to changes over time. Additionally, stating that fossils can only occur in certain sedimentary environments would limit the understanding of fossil distribution across various geologic settings.