Fossils and Fossil types
A fossil is the preserved remains or __________ of an organism that lived in the
__________. Fossils give clues to the __________of living things over the
__________of Earth, give clues to past __________and surface changes on Earth,
and give clues to changes that have occurred with __________over time.
There are different __________of fossils based on how they were __________.
The formation process of fossils varies depending on __________and under what
__________ conditions they formed. These include the formation process of
__________, cast, __________, preserved, __________, and __________fossils.
o Mold fossil – forms when sediments __________an organism and the
sediments __________into rock; the organism __________leaving a cavity in the
shape of the __________.
o Cast fossil – forms when a __________is filled with __________or mud that
__________into the shape of the organism.
o Petrified fossil (permineralized fossil) – forms when __________soak into the
buried __________, replacing the remains, and __________them into
__________.
o Preserved fossil – forms when __________organisms or __________of
organisms are prevented from __________by being trapped in __________, ice,
tar, or __________.
o Carbonized fossil – forms when __________or parts, like __________, stems,
__________, fish, are pressed __________ layers of soft __________or clay that
hardens __________almost all the decaying organism away leaving the carbon
__________in the rock.
o Trace fossil – forms when the __________or sand hardens to __________where
a footprint, __________, or burrow of an organism was left __________.
Fossils and Fossil types
A fossil is the preserved remains or traces of an organism that lived in the past. Fossils give
clues to the diversity of living things over the history of Earth, give clues to past climate and
surface changes on Earth, and give clues to changes that have occurred with organisms over
time.
There are different types of fossils based on how they were formed. The formation process
of fossils varies depending on where and under what environmental conditions they formed.
These include the formation process of mold, cast, petrified, preserved, carbonized, and
trace fossils.
o Mold fossil – forms when sediments bury an organism and the sediments change into rock;
the organism decays leaving a cavity in the shape of the organism.
o Cast fossil – forms when a mold is filled with sand or mud that hardens into the shape of
the organism.
o Petrified fossil (permineralized fossil) – forms when minerals soak into the buried remains,
replacing the remains, and changing them into rock.
o Preserved fossil – forms when entire organisms or parts of organisms are prevented from
decaying by being trapped in rock, ice, tar, or amber.
o Carbonized fossil – forms when organisms or parts, like leaves, stems, flowers, fish, are
pressed between layers of soft mud or clay that hardens squeezing almost all the decaying
organism away leaving the carbon imprint in the rock.
o Trace fossil – forms when the mud or sand hardens to stone where a footprint, trail, or
burrow of an organism was left behind.