Mammal classified

All living creatures are classified by a seven-level system.  The top level is kingdom, followed by phylum, and then class.  In this particular case, the system is animalia, chordata, and the mammalia, or mammals.  Mammals are animals which are warm-blooded, have fur, and live young.  They are classified further into 3 subclasses and then into 26 orders.  Mammals make up a significant portion of the visible species on earth, and include humans and all house pets.
The first subclass is called Eutheria.  In includes these orders: Artiodactyla (deer, camels, pigs, cows, sheep, etc.), Carnivora (cats, bears, etc.), Cetacea (whales, dolphins), Chiroptera (bats), Insectivora (hedgehogs, moles, shrews), Lagomorpha (rabbits, hares), Perissodactyla (horses, rhinos, tapirs), Primates (apes, monkeys, lemurs, people), Proboscidea (elephants, etc.), Rodentia (rats, etc.), Sirenia (sea cows, manatees), Tubulidentata (aardvarks), and more (www.enchantedlearning.com).  These are the most familiar mammals to people, and it is also the largest subclass.  Other subclasses are Metatheria (marsupials) and Protheria.
Each order contains a number of different animals, which are all similar to each other in certain ways.  For example, “artiodactlya” contains animals that have an even number of toes, while “perissodactyla” contains animals that have an odd number of toes.  Both classes are similar, in that they both have large animals.  “Primates” is possibly the most familiar class, and it contains humans and monkeys, which are very similar, in having body hair and opposable thumbs.

Classifying mammals allows scientists to understand the features of the different groups.  While all mammals reproduce sexually and have live young, the gestational periods are different in different classes.  Knowing the differences helps to understand the different animals that scientists and people encounter.
Mammal classifications are very helpful in understanding the similarities and differences between types of animals.  It helps scientists to understand and order the world around them, and is a useful and necessary system.