Class Mammalia

1. Order Carnivora

   1. seals

   2. sea lions

   3. walruses

   4. otters

   5. polar bears

2. Order Sirenia

   1. manatees

   2. dugongs

3. Order Cetartiodactyla

   1. whales

   2. dolphins

   3. porpoises
      

Order Carnivora

• Suborder Pinnipedia

1. Family Otariidae

   1. Fur seals

   2. sea lions

2. Family Phocidae

   1. True Seals

3. Family Odobenidae

   1. Walrus

1. Family Mustelidae

   1. Otters

2. Family Ursidae

   1. Polar bear

Order Sirenia

1. Family Trichechidae

   1. Manatees

2. Family Dugongidae

   1. Dugongs

Order Cetartiodactyla (Cetacea)

1. Suborder Odontoceti

   1. Dolphins

   2. Porpoises

2. Suborder Mysticeti

   1. Baleen whales

Morphology of polar bears

• Specialized fur for a cold habitat

  • Black skin absorbs heat from the sun

  • Translucent fur = hallow hair fibers to allow more sunlight to be absorbed while also insulating

• Layer of fat to help retain body heat Helps to keep them warm when they are wet (fur is useless as an insulator when wet)

  • Polar bear vs grizzly Polar bears are bigger

    • have longer necks to help with feeding to grab prey in ice holes without wetting their entire body

    • small ears to minimize the icy water access to the ear canals

• Swimming

  • Forelimbs paddle Modified paddle paws

  • 5 toes with slight webbing and claws

• Hallow hair fibers and fat layer act as buoyancy

Morphology of sea otter

• Lack of adaptations to make life adjustments in water

• Streamline body (Minimize the body size ratio)

  • Don’t have a thick fat layer to rely on when wet

• Short legs (better insulated when limbs are small) and web feet (help swim) Flat tail

• Extremely Dense fur coats

  • semi-waterproof layer

• Thermo reg

  • They fluff the fur = to create air pockets to help with insulation

  • dense wet fur = a semi-waterproof layer