GEOLOGY

Detailed explanation-1: -Its bones are protected from rotting by layers of sediment. As its body decomposes all the fleshy parts wear away and only the hard parts, like bones, teeth, and horns, are left behind.

Detailed explanation-2: -Fossils also include any preserved trace of life that is typically more than 10 000 years old. Soft body parts decay soon after death, but the hard parts, such as bones, shells and teeth can be replaced by minerals that harden into rock.

Detailed explanation-3: -Bones and shells decompose much more slowly. Over long times, their mineral materials dissolve. That can happen rapidly when the shells and bones lie on the ground surface or on the sea bottom. If the shell or bone is buried in sediment, it dissolves more slowly.

Detailed explanation-4: -For a soft-bodied animal to be fossilized, its body must be protected from decomposition. The body is usually exposed to air and water with a lot of oxygen, so it decomposes rapidly. The animal is likely to be fossilized only if it is buried soon after it dies (or when it is buried alive!).