Under certain conditions fossils might not have been created. Parts of organisms do not always decay because the conditions needed might be absent, and so they may be preserved in different ways. For example, dead animals and plants can be preserved in amber, peat bogs, tar pits, or in ice.
Amber is a substance that is formed from hardened tree sap or resin. This allows the whole organism to be seen clearly.
Britain's most famous peat bog body is known as the Lindow man. The acidic, oxygen-free conditions in the peat bog meant that the man's skin, hair and many of his internal organs were extremely well preserved, which is very unusual, as this does not occur with rock fossils. As more the of the Lindow man's DNA is preserved, it enables scientists to learn more about that era and how we may have evolved from the time that the man was alive.
Another well-known example of a body preserved in ice is Oetzi. He was a mummified ancient man found in 1991, near the Austrian Italian border. Detailed analysis of his body indicated that he was approximately 5,000-years-old. His body has been extensively examined, including his gut bacteria and pollen contained on some clothes.