Bearded seal (Erignathus barbatus) is found in both the northern Atlantic and northern Pacific oceans. These seals can be found in ice covered areas, and also they are known to be found as far south as Newfoundland and northern Japan. They are circumpolar in distribution.

This unusual seal has very short forelimbs. These limbs end in a squared off manner with five strong claws. The male can reach almost 7 feet in length, while the female can be somewhat longer.

The Pacific Ocean population has been estimated to have 300,000 to 450,000 individuals. The Bering Sea portion containing about 250,000 individuals. Although hunted by natives in Alaska, the harvest rate is not alarming compared to existing populations.

Heavy and extensive ice in the 1970s caused a decline in populations.

True seals or earless seals (Family Phocidae) are found at both poles and in the Mediterranean. The twenty species are organized into thirteen different genera.

A partial list of the seals is as follows:

SPECIES - - - - - - COMMON NAME - - - - LOCATION
Cystophora cristata - Hooded - N. Atlantic, Arctic Ocean
Erignathus barbatus - Bearded - Arctic
Halichoerus grypus - Gray - North Atlantic
Histriophoca fasciata - Ribbon - Arctic Ocean, Alaska

Hydrurga leptonyx - Sea Leopard - South Pacific
Leptonychotes weddeli - Weddell's - South Pacific
Lobodon carcinophagus - Crab Eating - Antarctic
Mirounga angustirostris - Elephant - California

Mirounga leonina - S. Elephant - S. Atlantic & S. Pacific
Monachus schauinslandi - Hawaii - Hawaiian Islands
Monachus monachus - Monk - Mediterranean
Monachus tropicalis - Car. Monk - Caribbean

Pagophilus groenlandicus - Harp - Arctic, North Atlantic
Phoca vitulina - Harbor - Widespread N Hemisphere
Pusa hispida - Ringed - Arctic Ocean, etceteras
Pusa sibirica - Nerpa - Lake Baikal in N. Eurasia

Walruses and Seals (Order Pinnipedia) are a group of marine animals that are especially abundant in cold areas particularly near the poles. These animals are characterized by front and rear legs that have modified into flippers for swimming. They spend most of their lives in water, and are not especially adapted for living on land. Most species feed on fish, marine Crustacea, and other vertebrates. Because these animals are closely related to the carnivores, they could be combined with the carnivore group into one large order.

This order appears not to be valid under a Hennigean-Cladistic taxonomy. The eared seals (Family Otaridae) evolved from dog like carnivores about 25 million years ago, and the true seals (Phocidae) appeared to have evolved about 15 million years ago from otter like carnivores.

Although most modern scientists would move these animals into the Carnivore Order, we have retained them as a separate order. The science of cladistics would have us place one family under the Canis genus, and another family under the otters or under the Mustelidae. (We believe that if we restated the taxonomic tree in line with the latest evolutionary thinking, we would end up with an enormous number of levels. We believe the taxonomic drill down is a valuable tool for environmentalists, nature lovers, and even for scientific specialists.)

Mammals (Class Mammalia), together with the birds, are among the youngest of the classes of animals. In species count, mammals number about fifty-one hundred, trailing reptiles (approximately fifty-five hundred), fish (approximately eighteen thousand), and birds (approximately eighty-six hundred).

There are three sub-types of mammals:

monotremes, the most primitive:
Develop in reptilian-like eggs and suckle milk emerging (i.e., spiny anteater, duckbilled platypus)
marsupials
Newborn emerges very underdeveloped and continue to mature in a pouch on its mother's abdomen (i.e., opossums, koala, kangaroo)
placental
Embryo develops within the uterus of the female and is dependent on a placenta for nutrition and waste removal (i.e., humans, lions, monkeys)

About sixty-five million years ago, the Tertiary era produced thirty-five orders of mammals. Of this number, eighteen have survived to represent Earth's most diversified as well as its most highly developed classification of animals.

Extinction of mammals is fast becoming a serious issue. Duff and Lawson present a list of forty-one extinct species that reached extinction prior to 1800. These forty-one species are not acknowledged in the counts of the various families. Duff and Lawson also present a list of forty-six species including three gazelles, one zebra, one seal, one deer, and one wolf that have probably gone extinct since 1800. These forty-six species are included in the family counts. Science is adding about forty to fifty new species a year to the list. Many of these are the result of divisions of prior species; some are recent discoveries.

Mammals owe their survival to adaptive capabilities that include the ability to exploit whatever sources of food are available to them, as well as their ability to adjust to various climes. Food specialization influenced evolution to such a great extent that the teeth structure can and has been used to provide extensive information on the food needs and various lifestyles of extinct species.

Despite the vast diversity among mammals in terms of size, habitats and adaptations, they share without exception many characteristics such as:

a. body hair
b. mammary glands
c. certain skull characteristics
d. four limbs that permit speed
e. parallel not perpendicular limbs
f. compartmentalized internal organs
g. a four-chambered heart and pulmonary circulation

Backboned Animals (Phylum Chordata) are the most advanced group of animals on earth. These animals are characterized by having a spinal cord or backbone. Most members have a clearly defined brain that controls the organism through a spinal cord. Fish, amphibians, reptiles, birds, and mammals are in this phylum.

Currently, some taxonomists believe that the fish should be divided into two groups (sharks and regular fishes) and that there are some other primitive groups in the phylum such as hagfish or lampreys.

Animal Kingdom contains numerous organisms that feed on other animals or plants. Included in the animal kingdom are the lower marine invertebrates such as sponges and corals, the jointed legged animals such as insects and spiders, and the backboned animals such as fish, amphibians, reptiles, birds, and mammals.

NEW SEARCH