A lengthy scholarly article that discusses the geologic time scale, its history of development, age-dating events that occurred in different eras, and how absolute and relative dating are used to assess the ages of the Earth and Moon....

An overview of the different geologic time periods and how each affected the area of what is now the state of Arkansas.

This resource provides detailed information on each of the periods within the Precambrian Era. It discusses what earth was like, what the first multiple cell organisms were like and when they appeared.

Learn the basic information about the Mesozoic Era in Earth's geologic history.

A brief overview illustrating the Paleozoic era in Earth's geologic history.

Provides a detailed discussion of the Paleozoic Era and a timeline of its periods and epochs. Looks at geological and tectonic events, climate changes, flora and fauna, and a mass extinction event.

Provides an overview of the Mesozoic Era, its time frame, geological and tectonic activities, the climate, plants and animals, and extinction events towards the end of this era.

In this geoscience all day field activity at Interstate State Park at Taylors Falls, MN, students investigate and explore three events in Minnesota geological history.

This timeline is a good resource if you are looking for brief descriptions of the geologic periods. Descriptions include pictures of common organisms for each period and the range of time covered by each period.

Here is an excellent example of a picture timeline. Follow the Eras of the Earth from Cenozoic all the way down to Precambrian with the use of fossils.

This 2-page handout provides short descriptions of the different aeons, eras, and periods in the Earth's geological history.

A good brief review of The Cenozoic Era, which also includes links to more detailed information as well as a chart of its subdivisions.

What kind of evidence could demonstrate that humans have begun to dominate and alter the life systems of Earth and have entered a new geological epoch? This article discusses the suggestion that we have entered the Anthropocene and...

Identify geologic time periods and the animals and plants that lived during that time period.

This activity is specifically designed for a field trip to Drayton Hall, which is a historic plantation near Charleston, South Carolina. It does provide a model of how a similar activity could be designed for a local area, and there are...

If you need examples of index fossils for each of the geologic eras and periods, than this resource is for you. Diagrams of the index fossils and their scientific names are also provided.

Travel through Earth's history to learn about the Oligocene time period, which is characterized by the appearance of most of the living families of mammals.

The Mesozoic era is the period in which the dinosaurs existed. It encompasses three main geological periods - the Triassic, Jurassic and Cretaceous eras. The evolution of different life forms throughout these eras is described in this...

Engaging and interactive timeline with illustrations and video on the origin of the Earth takes us from the Archean Era to the Cenozoic.

This interactive timeline reveals key geologic and biological events starting back 4.8 billion years to the present.

A bullet list of important events in Earth's history broken down by eons, eras, periods, and epochs.

This site contains a chart showing the progression of the Paleozoic Era. Each section of the chart leads to information about the geological, biological, and climatic elements of a specific period of the era.

Two-part lesson plan in which students learn about when and how coal was formed. They will do research on geologic time frames and order them by eon, era, period, or epoch.

This comprehensive study guide covers the main terms and concepts needed for a unit on the evolution of multicellular life.