Phylum Chordata

Subphylum Vertebrata

Class Mammalia


Body Structure


One of mammals many body structures is their hair. Mammals have hair that hold heat. Another is their spine. All mammals have spines.
Mammals are vertebrates which means all mammals have an internal bony support structure were the ligaments and muscles are attached to the bony support. Their lungs are made of a spongy material coated with epithelium. This all happens in the diaphragm, located in the thorax. A mammals heart has four chambers. The right and left atrium, and the right and left ventricle. Atriums receive the blood, and the ventricles pump it out. All mammalian brains have a neocortex, which is unique to the mammal.



Obtaining Food


Mammals eat a broad variety of food. Mammals are so diverse, that they obtain food in many different ways. Most carnivorous mammals will hunt down their prey, while herbivores will simply eat leaves off a tree. Others can be omnivores. Most mammals have teeth. There teeth include Incisors, molars, canines, and premolars. They are used to help chew there prey and eat them. Mammals eat a lot to maintain their body temperature. All mammal infants feed off milk of their mothers. This is the easiest and sometimes only way to obtain food for newborns. Mammals have two digestive holes, the mouth and the anus. Food goes in through the mouth and through the digestive system then out through the anus.



Reproduction


Mammals reproduce sexually. Most mammals give birth to live young, but some lay eggs. Generally, most mammal species are either polygynous, one male mates with multiple females, or promiscuous (both males and females have multiple mates in a given reproductive season). Because females incur such high costs during gestation and lactation, it is often the case that male mammals can produce many more offspring in a mating season than can females. Most mammals give birth to live young but some, such as the monotremes lay eggs. Alive birth also occurs in some non-mammal species, such as guppies, snakes, and hammer heads, though it is not a differentiating characteristic of mammals.When a most mammals give birth they breast feed there young for about six months.



Movement


The majority of mammals travel across land, and move very often and further. The reason that they can move much farther is that their legs are under their body instead of on the side of them like reptiles. There are more than 30 types of movement that an mammal can do. Trotting, walking, and galloping are types of transportation that an mammal can do. The fastest mammal is the cheetah which can reach a speed of 60 mph. One of the slowest mammals is the camel which reaches a speed of 10 mph.



Adaptations


Mammals keep a steady endothermic temperature no matter there surroundings that has helped them live in a variety of habitats. Mammals are also warm blooded so they don't need sun to be able to move. They can adapt almost anywhere in almost no problem. They have fur that protects them from injury, keeps them warm, and camouflages them.


Importance to Humans


Mammals are important to humans because they provide us a well needed food source which our body breaks down into energy. Mammals are also important to humans because humans are mammals. In addition, mammals are at the top of the food chain, so lower species would overpopulate uncontrollably without mammals.


Infraclasses


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Prototheria (Egg-Laying Mammals)

This group is called monotremes. These mammals live in Australia and New Zealand, and lay eggs to reproduce. The Duck-billed Platypus and the Spiny Anteater are in this group.

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Metatheria (Marsupial Mammals)

Kangaroos and koalas raise their young in an outside pouch. This is called the Marsupial. When a baby is born they climb up the mother's fur into a pouch in the stomach. They are nursed until they can climb out from the pouch and go on their own.

Eutheria (Placental Mammals)

Placentals are the largest group of the mammals. Members of this group have young who develop fully inside the mother until they are ready to be born. Humans also belong to this group of mammals.


Orders (Placental Mammals)


sea_lions.jpgCetacean (Marine Mammals)
There are 120 different species of marine mammals. Some of them include: whales, dolphins, and porpoises. Obviously, marine mammals live in the ocean. They have lungs, and cannot breathe underwater. However, some of them can hold their breath under water for long periods of time. The polar bear is also usually grouped with the marine mammals.
Marine mammals evolved from land dwelling ancestors and share several adaptive features for life at sea such as generally large size, hydrodynamic body shapes, modified appendages and various thermoregulatory adaptations. Different species are, however, adapted to marine life to varying degrees. The most fully adapted are the cetaceans and the sirenians, whose entire life cycle takes place under water, whereas the other groups spend at least some time on land.
Polar bears are carnivores, feeding primarily on Arctic ringed seals. Their partially webbed paws allow them to swim, at a pace of six miles per hour, for up to 60 miles without rest. They live and hunt on frozen ice floes during winter months, and survive on berries and stored fat (and on human garbage in certain areas) when the short summer thaw forces them onto land, rendering seals inaccessible.
Polar bears, top predators in their arctic habitat, face growing threats to their survival from habitat loss and degradation, specifically from:
climate change and sea ice reduction, environmental contaminants and chemical pollutants, hunting and capture for public display.

fruitbat.jpgChiroptera (Flying Mammals)

Some of the flying mammals include bats. A bat is a mammal in the Chiroptera order. Their most recognizable feature is that their forelimbs are developed as wings, making them the only mammals in the world naturally capable of flight. Other mammals, such as flying squirrels, gliding flying possums, and calugos can glide for restricted distance.


South_American_Mammals-00.JPGCingulata (Toothless Mammals)

Some toothless mammals include the sloth, armadillo and the anteater. They have no teeth in the front and therefore, appear toothless.

rabbits.jpgLagomorpha (Rabbits and Hares)
Members of order Lagomorpha can resemble rodents (order Rodentia).





mammals6.jpgCarnivora (Carnivores)
The carnivores are meat-eaters, although not all carnivores eat meat only. Some that are in this group would be the African Buffalo, and the lion.


Proboscidea.jpgProboscidia (Mammals with trunks)
Elephants are mammals with trunks. There are three non-extinct types of elephants: the African Bush Elephant, the African Forest Elephant, and the Asian Elephant. All the other elephants have been extinct since the last ice age. The Mammoth would be one of the extinct elephants.African elephants are distinguished from Asian elephants in several ways. The most noticeable way that they are different from Asian elephants is their ears. Africans' ears are much larger. The African Elephant is usually larger than the Asian Elephant and has a concave back. African males and females have external tusks, and are usually less hairy than their Asian cousins.



07Mammals2.jpgRodentia (Rodents)
40% of mammal species are rodents.They are found in large numbers on all continents, other than Antarctica. Common rodents include mice, rats, squirrels, chipmunks, gophers, porcupines, beavers, hamsters, gerbils, and guinea pigs. Rodents are classified by two of their teeth that keep growing all throughout their lives. They have to have hard and sturdy things to chew on to prevent their teeth from becoming too long for their mouths.


hedgehog3.jpgSoricomorpha (Insect-eaters)
Insectivores are mammals who eat insects. Hedgehogs, shrews, and moles are all insectivores. There are around 430 species of insectivores. Their brains are usually on the small side, and they have unspecialized teeth. They usually have poor eyesight, a small, pointed nose, and little ears.




Mammals3.jpgPerissodactyla (Hoofed Mammals)
Some hoofed mammals include: the horse, the rhinoceroses, and tapirs. They are found all over the world. The horse and the donkey are a couple of hoofed mammals that have been domesticated. Perissodactlya range from 200 grams to 3,500 grams in mass.


clever-monkeys.jpgPrimates

Primates include monkeys, lemurs, apes, and humans. They are found all over the world. Non-human primates are commonly found in Central and South America, South Asia, and Africa. Non-human primates live in varied forest habitats, such as mountain forests, mangrove forests, and rain forests. All primates have five fingers, and fingernails. They also have opposing thumbs.



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