earths history __________________ - a timeline that organizes the events in earths history like a...
TRANSCRIPT
Earth’s History
__________________ - a timeline that organizes the events in Earth’s history
Like a calendar extending from Earth’s formation to the present
Divided into eons, eras, periods, and epochs
Earth’s History
www.fas.org
•________-the largest group; divided by the Cambrian boundary (about 550 million years ago) when the variety of life forms explodes; billions of years long
•____________: mass extinctions mark the boundaries between the eras; hundreds of millions years long
•_______________: blocks of time when a unique rock series was laid down; tens of millions of years long
•________________: divisions of the most recent periods; several million years long
•________________________________________________________________________________________
•Typically form in ______________________, however:
•May form in rocks
•Amber
•Petrification
•Asphalt
•Frozen Fossils
•______________________ - any naturally preserved evidence of animal activity
•__________-a cavity in rock where a plant or animal was buried
•___________-created when sediment fills in a mold and becomes rock
History of Change
•The fossil record reveals a history of environmental change. Why?
•Studying the relationship between older and younger fossils
•Fossils of organisms that lived during a relatively short, well-defined geologic time span
•Found in rock layers throughout the worldAmmonites 230-208
MYA
louisvillefossils.blogspot.com/2010/01/remark...
brianlean.wordpress.com/2008/08/
Trilobite ~400 MYA
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