Organisms from the Class Mammalia came from reptiles that branched off at the base of the reptillian tree. The two biggest characteristcs that distinguish mammalia is that they have hair or fur and have mammary glands to feed their young. Mammalia are endothermic which means they are warm blooded and can maintain theyre body temp no matter what the evironmental temperature is. Mammalia are viviparous which means their offspring develops inside them before they are born. The organisms have a single dentary bone in the lower jaw as well as a mucular diaphragm.
Moose (Alces Alces)
Diversity of vertebrates. (2010). Retrieved from http://www.shsu.edu/~bio_mlt/Chapter3.html
