Seal (mammal)
Otariidae
Phocidae
Odobenidae
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Pinnipeds are large marine
mammals belonging to the
Pinnipedia, a
suborder of the
order Carnivora. The
true seals,
sea lions,
fur seals and
Walrus are all pinnipeds.
Pinnipeds are typically sleek bodied and rather large. The smallest pinniped, the
Galapagos Fur Seal weighs about 30 kg when full-grown and is 1.2 metres long; the largest, the male
Southern Elephant Seal, is over 4 metres long and weighs up to 2,200 kg. All are carnivorous and live on fish, shellfish, squid, and other marine creatures.
It has long been believed that the pinnipeds are descended from a land-based carnivore, something approximately like a dog that has undergone
aquatic adaptation. During the
20th century there was considerable debate about the relationship between them; some
taxonomists maintaining the traditional view that they share a common ancestor, others suggesting that the
eared seals (sea lions and fur seals) are distinct from the
true seals, and that the similarities between the two groups are the result of
convergent evolution. If this were so, Pinnipedia would be a
paraphyletic grouping with no taxonomic meaning. Recent studies of
mitochondrial DNA, however, have strongly supported the
monophyletic hypothesis: that is, the evidence is currently on the side of a single-ancestor theory.
- ORDER CARNIVORA
- Suborder Fissipedia: cats, dogs, bears, raccoons, weasels, and many others
- Suborder Pinnipedia
