Question
• How do you think fossils form?
• What do you think that fossils tell us?
Fossils
• Are preserved
remains or traces of
living things.
• Provide evidence of
how life has
changed over time.
How fossils form
• Most form when
living things die and
are buried by
sediments
• Sediments slowly
harden into rock and
preserve the shapes
of the organisms
Sedimentary rock
• Fossils usually
found in this
• Rock is made of
hardened sediment.
Found
• Most found in
animals and plants
that lived in or near
quiet water such as
swamps, lakes, or
shallow seas.
• Dies = hardens and
only hard parts
leave fossils
Found
• Fossils found in rock
include molds and
casts, petrified
fossils, carbon films,
and trace fossils.
• Others preserved in
tar, amber or ice
Mold
• Is a hollow area in
sediment in the
shape of an
organism or part of
an organism
• Forms when hard
part such as a shell
is buried in sediment
Cast
• Fossil that is a copy
of an organisms
shape formed when
minerals seep into a
mold
Petrified fossils
• Are fossils in which
minerals replace all
or part of an
organism
Carbon film
• Extremely thin
coating of carbon on
rock
Trace fossils
• Provide evidence of
the activities of
ancient organism.
• Ex fossil footprints,
trails, and burrows
Paleontologists
• Collect and classify
fossils
Fossil record
• Provides evidence
about the history of
life on earth
• Shows that groups
of organisms have
changed over time
• Shows fossils occur
in a particular order
Scientific theory
• Well tested concept
that explains a wide
range of
observations
evolution
• Is the gradual
change in living
things over long
periods of time
• Fossil record shows
millions of type of
organisms have
evolved.
Extinct
• No longer exists and
will never live on
earth again