16. See Timeline
17. See Continental drift chart and notes from class
18. The Phanerozoic rocks are divided by two large "gaps" (actually changes) in the kinds of fossils found caused by the great losses (extinctions) of ancient organisms that occurred at the end of the Permian Period of the Paleozoic Era and the end of the Cretaceous Period of the Mesozoic Era.
19. Among others, the seeded plants, the flowering plants, the marsupial mammals and the dinosaurs.
20. See notes and texts.