EOG Review: Earth's History

Reptiles were the dominant animals of this era, including the various dinosaurs

• Paleozoic Era

• Mesozoic Era

• Cenozoic Era

Began with the early invertebrates, such as trilobites and brachiopods.

• Precambrian

• Cenozoic Era

• Paleozoic Era

• Mesozoic Era

Information about past life, including the structure of organisms, what they ate, what ate them, in what environment they lived and the order in which they lived.

• extinction

• fossil record

• geologic time

A record of the geologic events and life forms in Earth's history.

• fossil record

• Geologic time

• extinction

The preserved remains or traces of an organism that lived in the past.

• extinction

• fossil record

• geologic time

• fossil

Earth's first era of time. Began with the creation of Earth about 4.6 billion years ago.

• Paleozoic Era

• Cenozoic Era

• Precambrian

• Mesozoic Era

Diversity of life forms increased. Humans are a part of the most recent period of this era.

• Mesozoic Era

• Cenozoic Era

• Paleozoic Era

• Precambrian

A term that typically describes a species that no longer has any known living individuals.

• fossil record

• extinction

• geologic time

• fossil

The age of a rock given as the number of years since the rock formed.

• rock cycle

• relative age

• half life

• absolute age

A crablike invertebrate that is the most common fossil of the Cambrian Period.

• trilobite

• index fossil

• absolute age