Answer: B. Original Continuity
Explanation:
Original continuity is the concept that sediments are deposited horizontally at the original point of formation. This lateral deposit continues, layer by layer unless the sediments are interrupted by a barrier.
The two rocks on the opposite sides of the canyon were likely one body of rock due to their similar lithology and fossil content. It is likely that the canyon formed due to erosion over time, thereby creating a barrier between the rocks.
The fossil range can simply be defined as the time period in which an organism has existed, thus left fossil traces of its existence. The fossil range can be very short, medium, or long, thus usually there are limitations before certain type of organism evolves into another species, thus eliminating the ancestral organism from the fossil records. On the other hand, there are organisms that have incredibly big fossil ranges of several hundred million years, and since they emerged, they have remained almost unchanged. Those kind of fossil ranges are very rare though, and they don't represent the general picture. Most of the fossil ranges are between several thousand years and several million years, as that is usually how much a species exists, ending its reign, be it because of competition, changes in the environment, or big natural disaster.
