Geologic Timeline Flashcard_(Template)

Front

How long ago did the Earth form?

Back

4.6 billion years ago

Front

Which time period came first in the Geologic time?

Back

Precambrian Supereon

Front

When did life first appear on Earth according to the fossil record and geologic timeline?

Back

3.5 billion years ago

Front

During which time segment of the Geologic Time Scale did single celled organisms first appear?

Back

Archean Eon

Front

During which time segment of the Geologic Time Scale did multicellular organisms first appear?

Back

Rhyacian Period

Front

During which time segment of the Geologic Time Scale did dinosaurs live?

Back

Mesozoic Era

Front

The Cambrian Explosion refers to

Back

the sudden appearance of many different types organisms in the fossil record.

Front

The Law of Superposition helps scientists to determine what?

Back

The relative age of rock layers

Front

Which rock layer most likely contains fossils of the most recently evolved organisms? Options: 4, 3, 1, 2

Back

1

Front

Which fossil is relatively the oldest? Options: Trilobite, Ammonite, Crinoid, Gastropod

Back

Trilobite