Final answer:
The mammalian support system includes the skeletal structure and the circulatory system with distinctive features for arboreal species such as brachiation. Mammals are broadly classified into superorders based on structure and function, including reproductive strategies distinguishing placental mammals and marsupials.
Step-by-step explanation:
The mammalian support system refers to its skeletal system, which provides the framework and structure necessary for bodily support, movement, and protection of internal organs. When it comes to arboreal mammals, such as primates, they exhibit specializations like long front limbs that facilitate brachiation, which is the ability to swing from branch to branch. This adaptation helps them navigate the forest canopy efficiently.
In terms of reproduction, mammals are divided into two groups of therian mammals: placental mammals and marsupials. Placental mammals have a complex placenta that nurtures the fetus and allows for longer gestation periods, leading to the birth of more developed offspring. Marsupials, on the other hand, give birth to less-developed young that typically complete their development in a pouch. These adaptations illustrate the variety of strategies within the mammalian class to support and ensure the survival of offspring.