The mammals are the class of vertebrate animals characterized by the presence of mammary glands, which in females produce milk for the nourishment of young; the presence of hair or fur; and endothermic or "warm-blooded" bodies. The brain regulates endothermic and circulatory systems, including a four-chambered heart. Mammals encompass some 5,500 species (including Humans), distributed in about 1,200 genera, 152 families and up to 46 orders, though this varies with the classification scheme.
Phylogenetically, Mammalia is defined as all descendants of the most recent common ancestor of monotremes (e.g., echidnas and platypuses) and therian mammals (marsupials and placentals).

Arnold's Exotic Cat Breeders - Breeders of exotic cats: bobcats, servils, jungle cat; located in Okeechobee, Florida.
Meta Description: [ Arnold's Exotic Serval Breeders is located in Okeechobee, Fl. We have been breeding and exhibiting exotic cats for over eleven years. All of our kittens are bottle feed, hand raised in home and underfoot! We are a Serval breeder, Bobcat breeder, Jungle Cat breeder, and a Caracal breeder. ]
Chins and Quills - Message forum about chinchillas and hedgehogs. Topics include breeding, health, exercise, and behavior.
Pygmy Pets Exotic Animals - Information about keeping Sugar Gliders and Wallabies as pets.
Meta Description: [ Pygmy Pets Exotic Animals, Sugar Gliders, Gliders, Wallabies, Bennett, Breeders of Exotic Animals, Jack Russells ]
Valley Stables and Exotic Alternative Livestock - Breeding and information about llamas, african serval cats, miniature sicilian donkeys, bennett's wallabies and pygmy goats.
404
Wild Animals - Volunteer experts answer detailed questions about keeping wild animals such as llamas, ferrets, wolves, hedgehogs, and ocelots as pets.
Meta Description: [ About AllExperts: expert guidance from real people helping to answer your questions ]
| Wildlife Specials - Crocodile - Part 1 | |
| Next Video | |