What are three ways that dolphins and porpoises are related?
Dolphin, porpoise and whale are all included in order Cetacea under class Mammalia.
Both Dolphin and Porpoise are classified in same mammalian order Cetacea, the name derived from Greek ketos meaning huge fish.
- Both have streamlined body,
- forelimbs are modified in flippers,
- hindlimbs are vestigeal,
- both mainly eat fish.
Dolphins and porpoises are evolutionarily closely related because both are Toothed whales (as compared to the other group of Baleen whales).
All members of Cetacea are descendents of terrestrial ungulates. Primitive ancestors first took to the sea 50 million years ago. Around 35 million years ago there was a split in two distince lines: toothed whales developed a strong sense of echolocation.
These animals are widespread in distribution.