Taphonomy: The Science of Death and Decay

Taphonomy is the subdiscipline of paleontology related to the processes of fossilization. This includes all things that happen to the remains of an organism after it dies until it is observed or collected by a geoscientist. This might include the decay of soft tissues, the separation of skeletal hard parts, and chemical changes to the organism after burial. By studying these processes, we can also uncover clues about the environment in which the organism lived, died, and was preserved.

IS THIS A FOSSIL?

Consider the photo of Archaeopteryx on this page.  This image likely represents what many people think of when they hear the word “fossil:” bones of an ancient organism preserved in rock.  Indeed, it does include major components that define many fossils:  easily preservable hard parts (bones), a medium of preservation (surrounding rock), and its old.  Now think about a turkey leg your dog buries in your backyard. Is that a fossil? No, the turkey leg isn’t a fossil because it is too recent.  Officially, fossils are remains of organisms over 11,700 years old, which marks the boundary between the Pleistocene and Holocene Epochs.

Many fossils are body fossils, including mineralized hard parts (shells, bone) and a diverse array of soft tissues (like skin, feathers, flowers) from a previously living organism.  Trace fossils (such as burrows, nests, and coprolites) represent the activity of living organisms and are also found throughout the fossil record.  Preservation of both body and trace fossils typically occurs in lithified sediment, but body fossils may also be trapped in amber (fossilized tree resin), glacial ice, tar pits, or even lava.