Also question is, how are the three groups of mammals classified?
Mammals can be divided into three more groups based on how their babies develop. These three groups are monotremes, marsupials, and the largest group, placental mammals. Monotremes are mammals that lay eggs. The only monotremes that are alive today are the spiny anteater, or echidna, and the platypus.
What are the 5 classifications of animals?
The five most well known classes of vertebrates (animals with backbones) are mammals, birds, fish, reptiles, amphibians. They are all part of the phylum chordata — I remember “chordata” by thinking of spinal chord.
What are the three main subclasses of the mammals?
There are three subclasses of mammals: prototheria, metatheria and eutheria. Monotremata is the only order in the prototheria subclass. Monotremes are so different from other mammals that scientists think they may be descended from a separate mammal-like reptilian stock. The duck-billed platypus is in this order.