A fossil (from
Classical Latin
Classical Latin is the form of Literary Latin recognized as a literary standard by writers of the late Roman Republic and early Roman Empire. It was used from 75 BC to the 3rd century AD, when it developed into Late Latin. In some later pe ...
, ) is any preserved remains, impression, or trace of any once-living thing from a past
geological age. Examples include
bone
A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, an ...
s,
shells,
exoskeletons, stone imprints of animals or
microbes, objects preserved in
amber
Amber is fossilized tree resin that has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects."Amber" (2004). In M ...
,
hair,
petrified wood and
DNA remnants. The totality of fossils is known as the ''fossil record''.
Paleontology
Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fos ...
is the study of fossils: their age, method of formation, and
evolution
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...
ary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old
to 4.1 billion years old.
[ Early edition, published online before print.] The observation in the 19th century that certain fossils were associated with certain rock
strata led to the recognition of a
geological timescale and the
relative ages
Relative dating is the science of determining the relative order of past events (i.e., the age of an obj