The Geologic Time Scale
The layers of rock on Earth serve as evidence when identifying the geologic time scale. Using the fossil record, paleontologists have created a picture of the different types of common organisms in each geologic period.
The layers of rock on Earth serve as evidence when identifying the geologic time scale. Using the fossil record, paleontologists have created a picture of the different types of common organisms in each geologic period.
The geologic time scale is a record of the major events and diversity of life forms present in Earth's history. The geologic time scale began when earth was formed and continues to the present day.
Humans subdivide time into useable units such as our calendar year, months, weeks, and days; geologists also subdivide time. One way to distinguish and define each segment of time is by major geologic events and the appearance or disappearance of life-forms, starting with the formation of Earth.
Eras are divided into Periods and Periods are divided into Epochs.
Eras are divided into Periods and Periods are divided into Epochs.
The Precambrian was the earliest and longest span of time. It lasted from 4.6 billion years ago until 542 million years ago. It covers almost 90% of the entire history of earth. The oldest fossils and rocks date back to the Precambrian.
The Precambrian was the earliest and longest span of time. It lasted from 4.6 billion years ago until 542 million years ago. It covers almost 90% of the entire history of earth. The oldest fossils and rocks date back to the Precambrian.
The Paleozoic Era is known as the Age of Invertebrates. It begins with the Cambrian explosion and ends with a largest massive extinction ever-known as The Great Dying.
The Paleozoic Era is known as the Age of Invertebrates. It begins with the Cambrian explosion and ends with a largest massive extinction ever-known as The Great Dying.
The Mesozoic Era is known as the Age of Reptiles. It begins with the breaking apart of Pangaea. flowering plants and small mammals appear. It ends with the extinction of the dinosaurs.
The Mesozoic Era is known as the Age of Reptiles. It begins with the breaking apart of Pangaea. flowering plants and small mammals appear. It ends with the extinction of the dinosaurs.
The Cenozoic era is known as the Age of Mammals. It began with the extinction of the dinosaurs and continues today. The Cenozoic Era saw the rise of large mammals like the saber-toothed tiger and wooly mammoth. It is also where human life began.
The Cenozoic era is known as the Age of Mammals. It began with the extinction of the dinosaurs and continues today. The Cenozoic Era saw the rise of large mammals like the saber-toothed tiger and wooly mammoth. It is also where human life began.