G2
Lesson Summary
Vocabulary Link
- geologic timescale
- era
- Precambrian Time
- Paleozoic Era
- Mesozoic Era
- Cenozoic Era
- invertebrates
- Rodinia
- Laurentia
- period
- Laurasia
- Gondwana
- epochs
- Holocene Epoch
- Geologic time is broken down into four major eras; Precambrian Time, the Paleozoic Era, the Mesozoic Era, and the Cenozoic Era.
- These eras are based primarily on the life-forms that existed during these periods of time.
- Precambrian Time starts with the formation of the Earth, and ends with the origin of simple life; the world’s first supercontinent, Rodinia, forms.
- The Paleozoic Era marks the development of invertebrates, fishes, and amphibians; the supercontinent Pangaea forms.
- The Mesozoic Era is the age of reptiles with dinosaurs being the dominant life-form; Pangaea breaks apart, and the shapes of modern continents begin to form.
- The Cenozoic Era is the age of mammals with humans becoming the dominant life-form after the end of the last ice age; continents drift to their current positions.