Subfossil

A subfossil is a part of a dead organism that is partially, rather than fully, fossilized, as is a fossil. Partial fossilization may be present because not enough time has elapsed since the animal died for full fossilization, or because the conditions in which the remains were deposited were not optimal for fossilization.

A dodo skeleton subfossil

Unfossilized or partially fossilized remains can include bones, exoskeletons, nests, skin imprints, or fecal deposits. Subfossils of vertebrates are often found in caves or other shelters, where the remains have been preserved for thousands of years.[1] Subfossils are also often found in depositionary environments, such as lake sediments, oceanic sediments, and soils. Once deposited, physical and chemical weathering may alter the state of preservation, and small subfossils can also be ingested by living organisms. Subfossil remains that date from the Mesozoic are exceptionally rare, are usually in an advanced state of decay, and are consequently much disputed.[2] The vast bulk of subfossil material comes from Quaternary sediments, including many subfossilized chironomid head capsules, ostracod carapaces, diatoms, and foraminifera.