You are here:About>Education>Animals / Wildlife> Animal Profiles> Mammals> Characteristics of Mammals
About.comAnimals / Wildlife

Characteristics of Mammals

From Laura Klappenbach,
Your Guide to Animals / Wildlife.
FREE Newsletter. Sign Up Now!

Mammals display a remarkable array of adaptations that enable them to inhabit a wide range of habitats. Some of their characteristics are shared by no other groups of animals: hair, mammary glands, three specialized middle-ear bones.

Hair

Hair is a defining characteristic of mammals: no other organisms possess true hair and all mammals have hair covering at least part of their body at some time during their life. Hair grows from skin cells known as follicles. The hair shaft is made of a protein called keratin. Hair serves numerous functions.

Mammary Glands

Mammary glands, like hair, are a uniquely mammalian trait. Though present in both males and females, mammary glands only fully develop in females. Mammary glands consist of ducts and glandular tissues that secrete milk through nipples. Young mammals obtain milk from their mother by feeding from her nipples. The milk provides the young with much needed protein, sugars, fat, vitamins, and salts.

Three Middle Ear Bones

These ear bones (the malleus, incus, and stapes) transform sound vibrations into neural impulses.

Diaphram

Four-Chambered Heart

Large Cerebral Cortex

Newsletters & RSSEmail to a friendSubmit to Digg
 All Topics | Email Article | | |
Advertising Info | News & Events | Work at About | SiteMap | Reprints | HelpOur Story | Be a Guide
User Agreement | Ethics Policy | Patent Info. | Privacy Policy©2008 About, Inc., A part of The New York Times Company. All rights reserved.