Are mammals divided into sub groups?

Yes, mammals are divided into various subgroups, or taxa. The classification of mammals is extensive and hierarchical, with different levels of groupings based on evolutionary relationships and shared characteristics. Here are the primary subgroups of mammals:

1. Monotremes:

- Monotremes are the most primitive group of mammals and are unique in laying eggs rather than giving birth to live young.

- Examples include the platypus and echidna.

2. Marsupials:

- Marsupials are mammals that give birth to underdeveloped young, which continue their development in a pouch on the mother's body.

- Examples include kangaroos, koalas, and opossums.

3. Placentals:

- Placentals are the largest and most diverse group of mammals, characterized by the presence of a placenta during gestation, which allows for the exchange of nutrients and waste between the mother and developing offspring.

- Placentals include all other mammals not classified as monotremes or marsupials. They can be further divided into numerous orders, including:

a. Primates: Include humans, apes, monkeys, and lemurs.

b. Carnivora: Include cats, dogs, bears, and seals.

c. Rodentia: Include mice, rats, squirrels, and beavers.

d. Artiodactyla: Include cows, pigs, sheep, and deer.

e. Perissodactyla: Include horses, zebras, and rhinoceroses.

f. Cetacea: Include whales, dolphins, and porpoises.

g. Chiroptera: Include bats.

h. Lagomorpha: Include rabbits and hares.

i. Proboscidea: Include elephants.

j. Sirenia: Include dugongs and manatees.

This list represents some of the major subgroups within mammals, and each group may further branch into families, genera, and species as the classification becomes more specific.