Fossil Formation
by
CAL1363
Last updated 5 years ago
Discipline:
Social Studies Subject:
Prehistory
Grade:
7


fossils that provide evidence of the activities of ancient organisms
Petrified Fossils
fossils in which minerals replace all or part of an organism
Fossil Formation
Molds and Casts
mold:
a hollow area in sediment in the shape of an organism or part of an organism
cast:
a solid copy of the shape of an organism
How Fossils Are Formed
petrified fossils:
Trace Fossils
trace fossils:
From fossil footprints, scientists can find answers to questions about an animal's size and behavior. Other types of trace fossils also provide clues about ancient organisms.Ex: A trail or burrow can give clues about the size and shape of an organism, where it lived, and how it obtained food.
A fossil may form when the remains of an organism become petrified. As an example, fossil tree trunks are petrified wood. These fossils form after sediment covers the wood. Then, water rich in dissolved minerals came out of the solution and hardened.
Preserved Remains
tar:
sticky oil that seeps from Earth's surface
amber:
the hardened resin, or sap, of evergreen trees
Ways to Preserve Remains:
- organism becomes trapped in tar = tar soaks into organism's bones = no decay - organism is trapped in sticky resin = more resin covers it = sealing it from air/protecting its body from decay - freezing = frozen remains of woolly mammoths have been found in very cold regions of Siberia/Alaska = has preserved even the mammoth's hair & skin
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