The principle of fossil succession states that Choose one: A the same fossil assemblages appear throughout geologic time in repeating intervals. B. every rock layer contains only one species of fossil. C. every fossil species spans only a limited range of rock layers, corresponding to the time period over which it lived D. fossil species found in rock are the same as species living today.
The Correct Answer and Explanation is :
The correct answer is:
C. Every fossil species spans only a limited range of rock layers, corresponding to the time period over which it lived.
Explanation:
The principle of fossil succession is a fundamental concept in geology and paleontology. It was first recognized by the English geologist William Smith in the early 19th century. This principle states that fossil organisms succeed one another in a definite and recognizable order, and each fossil species appears within a specific time frame in the rock record.
Fossils are the preserved remains or traces of ancient life found in sedimentary rocks. When organisms die, their remains can become buried in layers of sediment. Over millions of years, these sediments harden into rock, preserving fossils within them. Because different organisms lived at different times in Earth’s history, their fossilized remains can be used to identify and correlate the age of rock layers.
Since every species has a limited time span during which it existed before going extinct, the fossils found in a particular layer represent the organisms that lived during that time period. Once a species becomes extinct, it does not reappear in younger rocks. This allows geologists to use fossils as index fossils to determine the relative ages of rock layers.
The principle of fossil succession is important for:
- Dating rock layers (relative dating)
- Understanding past environments and climate
- Correlating rock layers across different locations
Why the other options are incorrect:
- A is incorrect because fossil assemblages do not repeat in intervals. They follow an evolutionary sequence.
- B is incorrect because a single rock layer can contain multiple species of fossils.
- D is incorrect because most fossil species are extinct and differ from modern species.
This principle has been crucial in developing the geologic time scale and understanding the history of life on Earth.