Download What is a fossil?

{Paleontology
• pa·le·on·tol·o·gy
• ˌpālēənˈtäləjē/
• noun
• noun: palaeontology; noun: paleontology
• the branch of science concerned with fossil
animals and plants.
What is a fossil?
The preserved remains
of living things or
traces of living things.
These are often found
in sedimentary rock.
How do fossils form?
Organism dies and
sinks to the bottom.
Sediments cover the
organism.
The sediments become
rock, preserving parts
of the organism.
Millions of years pass….
Only the hard parts of
the organisms may
fossilize. Soft parts
decay too quickly.
Geologic events like
uplift, weathering, and
erosion bring the fossil
closer to the surface.
Fossil is exposed at the
surface.
What are the types of fossils?
•molds/casts
•trace
•petrified
•impressions
•carbon films
What is a trace fossil?
Traces of an organism’s activities
• burrows
• nests
• poop
• tracks
• trails
• footprints
An imprint
left behind
when an
organism is
covered by
sediments
before it
decays
Water and
sediment fills a
mold and
makes a copy
of an organism
cast
mold
Petrified fossils are created
when water containing
minerals seeps into the open
spaces found within an
organism. After millions of
years, these minerals
crystallize and form an
almost glass-like copy of the
organism.
Impression
Commonly made in
clay or silt, trace
fossils will fall into this
category. Plant leaves
are commonly found as
impressions.
Carbon Films
All organisms are made
of carbon. Sometimes,
when an organism
rapidly decays, the
carbon in their bodies
remains. This leaves a
perfect “shadow” of
the creature in carbon.