Linked from
The 25 pages that link to Evolution of cetaceans, each with the reason it gives.
CenozoicRelated: It is a striking Cenozoic example of mammals adapting to a new environment.
Toothed whaleRelated: Toothed whales inherited their aquatic body plan through this transition.
WhaleRelated: Whale anatomy makes sense in light of the group's transition from land to sea.
PorpoiseRelated: Porpoise bodies retain the result of cetaceans’ transition to aquatic life.
CetaceanRelated: It explains how terrestrial anatomy was transformed for life in water.
DelphinidaeRelated: It explains the aquatic ancestry shared by every delphinid.