Define:FossilCarbon film (carbonization)Petrified fossil (mineralization)Solid CastMoldTrace Fossil
The Fossil Record - Made up of all the fossils ever discovered on EarthProvides evidence about the
history of life and past environments on Earth
Also shows that species have changed over time
Where do fossils form?Fossils usually form in layers of
sedimentary rock Sedimentary rock forms when small
pieces of rock and other materials settle into layers that eventually harden.
The soft parts of the organisms quickly decay, but sometimes the hard parts, like shells and bones, leave fossils.
Other types of rock (igneous and metamorphic) form due to high heat and/or pressure, which destroys fossils.
Carbon films (Carbonization)Form when a dead organism is
compressed over time (due to layers of sediment forming on top of them). Eventually, only a carbon outline remains
Petrified Fossils (Mineralization)Mineralization occurs when rock
forming minerals in water replace all or part of an organism, basically turning it to stone
The minerals harden after the water dissolves, preserving the organism
Molds and CastsMolds occur when an organisms shell or
bone makes an impression in mud or sand that then hardens, preserving it
The mold can be later filled in by sediments to form a cast (3-D fossil copy)
Trace FossilsShow evidence of an organism’s
movement or behaviorUsually footprints
Original MaterialWhen an entire organism is
preserved Can occur due to being trapped in
amber (tree sap), freezing in ice, tar pits, etc.