Answer:
Fossils are defined as the ancient plants and animals that were buried millions of years ago. These are found to be present in the sedimentary rocks. They are often compared to a large jigsaw puzzle because most of their pieces are always found to be missing on the exposed areas. It is because they are buried deep within the earth's surface which is very difficult to obtain. These fossils are preserved only under certain favorable condition, and new fossils are discovered by the paleontologists in most of the places in the recent times, which are being used to study about the past stories.
This is how the fossil record can be related to a complex type of jigsaw puzzle.
