{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

MassExtinctions

MassExtinctions - Mass Extinctions Geology 331 Paleontology...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
Mass Extinctions Geology 331 Paleontology
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
The Phanerozoic Eons are divided by Mass Extinctions
Background image of page 2
How have physical changes on the earth effected the evolutionary history of life during the Phanerozoic?
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Types of Extinction Background Extinction ± when species go extinct through natural selection during gradual environmental change or competition between species Mass Extinction ± when large numbers of species go extinct together due to very unusual, environmentally catastrophic conditions. Usually unrelated to their normal adaptations to their environment. Is this natural selection at work?
Background image of page 4
Victims Ordovician ± over 50% of marine genera spread over about 100 families from several different groups Devonian ± about 40% of marine genera including all stromatoporoids, all shallow water corals, most trilobites
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
www.trilobites.info/biostratigraphy.htm Devonian mass extinction of 4 trilobite orders
Background image of page 6
Phacopids:
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}