All mammals share at least three characteristics not found in other animals: 3. middle ear bones hair, and the production of milk by modified sweat glands called mammary glands. The three middle ear bones, the malleus, incus, and stapes (more commonly referred to as the hammer, anvil, and stirrup) function in the transmission of vibrations from the tympanic membrane (eardrum) to the inner ear. The malleus and incus are derived from bones present in the lower jaw of mammalian ancestors. Mammalian hair is present in all mammals at some point in their development. Hair has several functions, including insulation, color patterning, and aiding in the sense of touch. All female mammals produce milk from their mammary glands in order to nourish newborn offspring. Thus, female mammals invest a great deal of energy caring for each of their offspring, a situation which has important ramifications in many aspects of mammalian evolution, ecology, and behavior.
Different species of mammals have evolved to live in nearly all terrestrial and aquatic habitats on the planet. Mammals inhabit every terrestrial biome, from deserts to tropical rainforests to polar icecaps. Many species are arboreal, spending most or all of their time in the forest canopy.
- most mammals have hair their entire lives. Adults of some species lose most or all of their hair but, even in mammals like whales hair is present at least during some phase of ontogeny. Mammalian hair, made of a protein called keratin, serves at least four functions. First, it slows the exchange of heat with the environment (insulation). Second, specialized hairs have a sensory function, letting an animal know when it is in contact with an object in its environment. Vibrissae are often richly innervated and well-supplied with muscles that control their position. Third, hair affects appearance through its color and pattern. It may serve to camouflage predators or prey, to warn predators of a defensive mechanism, or to communicate social information (for example, threats, such as the erect hair on the back of a wolf sex, such as the different colors of male and female monkeys or the presence of danger, such as the white underside of the tail.
- My order: Artiodactyla, Carnivora, Cetacea, Chiroptera, Dermoptera, Edentata and many more. All animals with backbones, including humans, are chordates. That is, in the language of taxonomy, they belong to the phylum Chordata. Their subphylum is Vertebrata, meaning that their backbones are segmented. Mammals, members of the class Mammalia of vertebrate animals that includes humans, are the most highly advanced organisms on Earth. They are warm-blooded, hairy, have four-chambered hearts, relatively large brains, and they suckle their young.There are 19 orders of mammals in the world. Ten of these live in North America. Some orders include a wide range of animals; for example, shrews, lemurs, marmosets, monkeys, apes, and humans are all primates, one order of the class of mammals. Other orders are made up of only one sort of creature; Order Chiroptera, or example, consists of 18 families of bats.The Latin names of the orders of mammals given here are followed by their common names and the families that make up each order. Examples of the various types of animals included in each family also are given.
There are currently 1260 genera, 156 families, 29 orders, and exactly 5877 species of described mammal, all in a single class. Using Groves and Grubbs' Taxonomy of Ungulates for the family Bovidae within Artiodactyla. The genus Bison is included within Bos in this classification and the genera Nyala, Strepsiceros (greater kudu), and Ammelaphus (lesser kudu) are all distinct genera from Tragelaphus (sitatunga, bushbuck, gedemsa or mountain nyala, and the bongo), this is supported by mtDNA. Many other recent advancements in mammal taxonomy have resulted in the description of new genera (Waiomys) and some genera have been combined (Uncia combined with Panthera), and other have been split (Niumbaha split from Glauconycteris).
- Alton Nobles