Class Mammalia
We will be working on class mammalia in this module. We all tend to have a good bit of experience with this class because cats, dogs, and humans fit into this classification.
Characteristics of Class Mammalia
There are five characteristics of class mammalia that we will be talking about. All mammals have hair. Hmmm, what about pigs? Do they have hair? They are mammals. The mammals are characterized by internal fertilization and most are viviparous. Viviparous means that they use an umbilical cords to get nutrients from the mother while in the womb. We will talk a good bit about gestation in mammals. Did you know that it only takes 3 weeks for a mouse to gestate (be ready for birth) but it takes a horse 13 months? All mammals will provide milk for their offspring for at least a short while, even whales (yes, they are mammals too). All mammals have a 4 chambered heart. Why do they need four chambers? The last characteristic is that they are endothermic. Endo means inside and thermic means heat. That means they maintain their own body temperature. If humans were not endothermic, what would happen to us in the winter in a northern climate?
Classification in Class Mammalia
bat faces
Can you think of some representative organisms in the following orders: monotremata, marsupial, chiroptera, carnivora, aquatic mammals, probosidea, hooved, rodentia, insectivora, primates, and aardvarks and anteaters each get their own order. Here is a good puzzler: Are armadillos classified as mammals? There is a picture of one that strolled across our yard and my daughter grabbed a picture of in the slide show. They don't see very well and this one was fairly oblivious to her presence. We have skunk too. Our cats know to stay back from the skunk when one occasionally comes up on the porch to see if there are any leftovers in the cat bowl at night. When the armadillo happens to decide to come up at the same time the confrontation over who gets dibs can get pretty smelly.