Marine Mammal - Taxonomy

Taxonomy

Mammals have returned to the water in at least nine separate evolutionary lineages (Cetacea, Sirenia, Desmostylia, Pinnipedia, Ursus maritimus (polar bear), Kolponomos (marine bear), Thalassocnus (aquatic sloth), Enhydra lutris (sea otter) and Lontra feline (marine otter)). Three of these lineages are extinct (Desmostylia; Kolponomos; Thalassocnus). Despite the diversity in morphology seen between groups, improving foraging efficiency has been the main driver in the evolution in these lineages. Today, marine mammals belong to one of three orders; Cetacea, Sirenia, or Carnivora. Within the Order Carnivora are the pinnipeds (sealions, walruses and seals), the polar bear (Ursus maritimus), and two otters (Endydra lutris and Lontra feline.

• Order Cetacea
  • Suborder Mysticeti (baleen whales)
    • Family Balaenidae (right and bowhead whales) = 2 genera; four species
    • Family Neobalaenidae (pygmy right whale) = one species
    • Family Balaenopteridae (rorquals) = 2 genera; 8 species
    • Family Eschrichtiidae (gray whale) = 1 species
  • Suborder Odontoceti (toothed whales)
    • Family Physeteridae (sperm whale) = 1 species
    • Family Kogiidae (pygmy and dwarf sperm whales = 1 genera; 2 species
    • Family Monodontidae (narwhal and beluga) = two genera; two species
    • Family Ziphiidae (beaked whales) = 6 genera; 21 species
    • Family Delphinidae (oceanic dolphins) = 17 genera; 36 species
    • Family Phocoenidae (porpoises) = 2 genera; 6 species
    • Family Platanistidae (South Asia river dolphin) = 1 species
    • Family Iniidae (boto) 1 species
    • Family Lipotidae (Baji) probably extinct
    • Family Pontoporiidae (franciscana) = 1 species
• Order Sirenia (sea cows)
  • • Family Trichechidae (manatees) = 1 genus; 3 species
    • Family Dugongidae (dugongs) = 1 species
• Order Carnivora (carnivores):
  • • Family Mustelidae (otters) Enhydra lutris (sea otter) Lontra feline (marine otter)
    • Family Ursidae (bears) Ursus maritimus (polar bear)
  • Suborder Pinnipedia (sealions, walruses, seals)
    • Family Otariidae (fur seals and sea lions) = 7 genera; 16 species
    • Family Odobenidae (walrus) = 1 species
    • Family Phocidae (true seals) = 13 genera; 18 species