what is a fossil?
Fossils are the preserved remains or traces of organisms that lived in the past (usually more than 10,000 years ago). Fossils are formed when an organism with hard parts (bones, teeth, etc.) is buried quickly, protected from scavengers, and eventually turns into rock. The Fossil Record gives important information about past life and environments on Earth, including extinctions and the appearance of new life forms.
Types of fossils
Mold-sediments bury an organism and turn into rock, leaving a cavity in the shape of the organism.
Cast-when a mold fossil is filled with sediment and hardens into the shape of the organism.
Petrified-minerals soak into the remains of an organism and turn into rock.
Preserved-an organism is prevented from decaying because it is trapped in ice, tar, amber, or rock.
Carbonized-organism is pressed between two layers of clay and hardens leaving a thin imprint in the rock.
Trace-remains of activity in rock where a footprint, trail, or burrow was made.
Cast-when a mold fossil is filled with sediment and hardens into the shape of the organism.
Petrified-minerals soak into the remains of an organism and turn into rock.
Preserved-an organism is prevented from decaying because it is trapped in ice, tar, amber, or rock.
Carbonized-organism is pressed between two layers of clay and hardens leaving a thin imprint in the rock.
Trace-remains of activity in rock where a footprint, trail, or burrow was made.