Precambrian Paleozoic Mesozoic Cenozoic

Precambrian, Paleozoic, Mesozoic, and Cenozoic all belong to:

• Epochs
• Eras
• Periods
• Eons

______ first appeared on Earth during the Triassic period. 

• Humans
• Dinosaurs
• Fish
• Modern Mammals

Age of fish was during this era:

• Cenozoic

• Mesozoic

• Paleozoic

• PreCambrian

Modern mammals was during this era:

• Cenozoic

• Mesozoic

• Paleozoic

• Precambrian

Age of reptiles was during this era:

• Cenozoic

• Mesozoic

• Paleozoic

• Precambrian

_____ were all extinct by the end of the Mesozoic Era

• Dinosaurs

• Modern Mammals

• Cyanobacteria

• gymnosperms

______ have been on Earth for about 200,000 years. This is very short compared to how long dinosaurs lived on Earth.

• Fish

• Humans

• Birds

• Insects

The earliest part of Earth's history is called the:

• Cenozoic
• Cambrian
• Holocene
• Precambrian

Which division of the geologic time scale is the longest?

• Eon
• Period
• Era
• Epoch

Which of these groups of animals appeared on Earth most recently?

• Reptiles
• Amphibians
• Mammals
• Fish