What is larger fossil or rock?
Originally... fossils form as pressure compresses soil materials
and forms rock. Rock is larger than the fossil it contains.
However, the rock can later fracture or split; the fossil inside
the rock can also be broken. But the fossil is still contained in
the rock, so rock is still larger until the fossil is mechanically
separated from the rock. However, if small, the indentation of
fossil can become only an etching in the rock.