20. The answer is 1 (Precambrian)
21. The answer is 4 (Pennsylvanian)
22. The answer is 2 (Bony Fishes, Dinosaurs, and Mammals)
23. The answer is 2 (Reptiles)
Answer:
meteorite striking the dinosaures
Answer:
c
Explanation:
The salinity of the water is increased.
Answer:
Habitat Isolation
Explanation:
Ecological, or habitat, isolation occurs when two species that could interbreed do not because the species live in different areas.
