Geological Time

4. eons are subdivided into smaller units of time called.
6. were dominant Mesozoic land vertebrates that walked with legs positioned directly below their hips.
7. connects two continents that were previously speparated.
9. Eras are subdivided into
11. Period is subdivided into
13. an ancient landmass which separated into present day continents
14. a body of water formed when ocean water floods continents

1. is a time when a large proportion of earth's surface is covered by glaciers
2. are grooves made by rocks carried in glaciers
3. were mesozoic marine reptiles with small heads, long necks, and flippers.
4. are the longest units of geologic time.
5. is the oldest era of the Phanerozoic eon.
8. era is the youngest era of the Phanerozoic eon.
10. is an oxygen-poor environment where, over time, plant material changes into coal.
12. was the middle era of the Phanerozoic eon.