A.Environmental characteristics like those present on ocean floors increase the likelihood that plant and animal fossils will occur.
B.The shells of organisms can be preserved by processes of chemical precipitation or mineral exchange.
C.Comparatively few fossils are found in the terrestrial deposits of streams and lakes.
D.Fossils are more likely to the preserved in shale deposits than in deposits of clay and silt.
E.Freezing enables the soft parts of organisms to survive longer than the hard parts.
F.Thin films of carbon may remain as an indication of soft tissue or actual tissue may be preserved if exposure to bacteria is limited