Across
- 1. Unit of geological time during which a rock series is deposited.
- 5. The dominance of gymnosperms and of archosaurian reptiles, such as the dinosaurs; a hot greenhouse climate; and the tectonic break-up of Pangaea.
- 6. A major division of geological time, subdivided into eras.
- 7. A major division of time that is a subdivision of an eon and is itself subdivided into periods.
- 8. Relating to or denoting the earliest eon of the earth's history, preceding the Cambrian period and the Phanerozoic eon.
Down
- 2. The first of three geological eras of the Phanerozoic Eon.
- 3. The most recent of the three major subdivisions of animal history.
- 4. The basic unit of geologic time.