Odobenus rosmarus - BIO203


Domain: Eukarya
Walruses have membrane bound organelles and a nucleus which is where genetic material is carried.

 Kingdom: Animalia
Walruses are multicellular which means they have many cells and  are  heterotrophic which means they cannot make their of food , so they have to obtain their food by hunting (Myers, P. 2001.).

 Phylum: Chordata
Walruses are vertebrates which means they have a vertebral column and  skeletal system for support. Also having a brain and spinal cord. Walruses have a closed circulatory system. They have a complete digestive system meaning they have two openings (one for food going in the other for waste coming out. Walruses are deuterostomes meaning they develop anus first instead of mouth first (Myers, P. 2001.).

Class:  Mammalia 
Walruses are warm blooded animals and have hair on their body. Walruses also have mammary glands, which are glands that produce milk for their young. They also have 3 middle ear bones which helps with picking up vibrations from the eardrum into the inside of the ear (Myers, P. 2001.).

Order: Pinniped
Walruses have webbed flippers to move through the water and  on land and have whiskers to help with obtaining food. They also have blubber to help with maintaining their body heat (Hamilton, C. and B. Kitchen).

Phylogeny of a Walrus in the pinnipeds

This is a the phylogeny of a walrus in the pinnipeds. It is comparing the walrus against its other pinniped members the Earless and Eared seals. Walruses are more closely related to Eared seals than Earless seals.

Family: Odobenidae
Walruses have back flippers that are able to rotate to help with walking. Enlarged canine teeth that are called tusks and do not have external ears (Hamilton, C. and B. Kitchen).

Genus: Odobenus
Literally means "tooth walker", they are called this because of how they use their tusks to pull their body up on top of ice (Sea World Parks and Entertainment).

Species: Odobenus rosmarus
There are two different species of the walrus: Atlantic walrus and the Pacific walrus. Of the two the Pacific walrus is bigger, has tusks that reach greater lengths, and their skull is wider (U.S. Fish and Wildlife Service. 1995; Sea World Parks and Entertainment).

This is a phylogeny of various species in the arctic regions.

After taking a look at the walruses phylogeny, you may want to check out their habitat.