Paleozoic Era

Cambrian PeriodDR. GREGG WILKERSON

Paleozoic

Life and Calcium Carbonate: 540 million years ago• Biogentic Limestones

The Cambrian Explosion of Life: 570 to 505 Million Years Ago• 25% Oxygen

• Great Diversity of Life

Trilobites

Cambrian Explosion

• All modern taxa and many extinct ones

The Great Cambrian Transgression• Shoreline

migrated inland in North America, east to west

• Observed in the Grand Canyon strata

Paleozoic Life

Precambrian to Devonian Life

Index fossils are diagnostic of a particular geologic period

Index fossilsof the Paleozoic

Cambrian Index Fossils

• Paradoxides pinus Billingsella corrugata

Caladonian Orogeny: 490–390 million years ago

• Caused by the closure of the Iapetus Ocean when the continents and terranes of Laurentia, Balticaand Avalonia collided

Phases of the Caladonian Orogeny

• East Greenland Orogen, formed from Cryogenian Neoproterozoic to Devonian

• Taconic phase – A mountain building period that affected most of New England in the NE U.S. and Canada during the Ordovician Period.

• Acadian phase in the Eastern U.S. during Silurian and Devonian Periods.

I Evolution of Earth

I will get an A on my exams and quizzes.

Discuss with a friend:

27. What is an index fossil?28.What did the world look like during the Cambrian? Insert an image for your answer.28.What were two index fossils for the Cambrian? Insert and image as part of your answer. Give the scientific names of the fossils.

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