Answer:
Fossils can be defined as the preserved remains and traces of ancient flora and fauna that were buried millions of years ago. These are found only in the sedimentary rock types as they are good rocks for the preservation of fossils.
In the given condition, there is an outcrop, where various species of fossils are found, of which one species ranges from 544 to 505 million years and the other has an age range of about 520 to 248 million years. So, the age of the rock shale comprising both this two fossils must have an age range of about 544 to 248 million years.