Geologic Time Scale

Complete the sentence.

"The geologic time scale is a record of _______________"

• the history of fossils only

• the history of rocks

• the history of rock layers and fossils

• geologist notes

What are remains of prehistoric life used to determine divisions in geologic time?

• Living organisms

• rock strata or layers

• DNA

• fossils

Which period are we currently in?

• Quaternary
• Holocene
• Jurassic
• Tertiary

What made Precambrian organisms to become extinct?

• Eventually, oxygen became abundant in the atmosphere.

• Carbon dioxide made most of the organisms suffocated.

• It happened due to large amount of methane accumulation.

• Nitrous oxide became poisonous.

During what Period were Dinosaurs present?

• Paleogene

• Quaternary

• Precambrian

• Jurassic

The time when the first jawed fishes and amphibians appeared

• Devonian

• Jurassic

• Cambrian

• Hadean

During what Period were Dinosaurs present?

• Paleogene

• Quaternary

• Precambrian

• Jurassic

During which periods did the first land plants, vertebrates, and insects appear?

• Jurassic-triassic

• Ordovician-silurian

• Hadean-acheon

• Tertiary-quaternary

Age of fish and amphibians

• extinction

• paleozoic era

• fossil record

• Precambrian era

The time when mammals became dominant

• Jurassic

• Oligocene

• Cambrian

• Hadean