Geologic Time

When did birds start to appear

• Cretaceous

• Triassic

• Tertiary

• Jurassic

When did oxygen become "plentiful"

• Mississippian

• Permain

• Cambrian

• Ordovician

When did the Cambrian Explosion happen

• About 543mya

• 2.5mya

• 3.8mya

• 490mya

What happened during the Devonian time

• Corals grouped together

• Fishes evolved

• Beginning of most life

• Huge bugs

What year did the Pennsylvanian time period end?

• 290

• 324

• 354

• 290

When is the Quaternary

• 1.8

• now

• 144

• 65

What is a Geological time scale

• Time that scales all animals

• Measurements

• A time scale that measures in ages, epochs, periods, eras and eons

• Different eras

When did the Permian Era end

• 417

• 324

• 290

• 248

What happened when the Cambrian Explosion took place?

• Everything dies

• Trees appear

• Things started to grow

• Oxygen and most life began

How do scientist know how old the fossils are

• Time Travel back to that time

• Look at the rocks

• The layers in the rocks

• Look at through the hole