What are the Primary Groups of Placental Mammal?

Marsupial mammals are one of the branches of mammals. They are characterized by no real placenta, so the fetus is born prematurely before it is fully developed. Premature babies will stay in the mother's nursery bag to suck milk and continue to grow. This type of animal is named after most of them having pocket-like nursery bags.

Marsupial mammal

Marsupials are one of the branches of mammals, and are characterized by no real placenta, so the fetus is born prematurely before it is fully developed, and premature babies will stay in the mother's nursery bag and continue to grow up by sucking milk. This type of animal is named after its pocket-like childcare bag. A childcare bag is a layer of skin covering the nipples. Such animals that survive today include kangaroos, belly mice and koalas.

125 million years ago, the subbeast subclass was differentiated from early mammals and evolved under the shadow of dinosaurs together with the mammals of the real beast subclass. 65 million years ago, after

In both regions, however, marsupials continue to survive in "Xanadu" isolated from the rest of the world. One area is Australia.

Marsupials are characterized by the lack of a true placenta and the immature development of cubs at birth and the need to rear their offspring in a nursery bag. It is only present in Oceania and South America and is very prosperous. Existing marsupials can be divided into the possum order (Opossum),

There are about 237 species of marsupials in existence, divided into opossum families,

Since the Europeans immigrated to Australia in 1788, many new animals have been introduced. The original living conditions of many marsupials have been destroyed. Due to various natural and social factors, 6 small kangaroos have become extinct. Due to the intensification of human economic activities, it will bring many adverse effects on the survival of marsupials in the future. At present, about 17 species of marsupials are listed in Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora. Included in Appendix II. If the living marsupials are not strictly protected, this group that is very unique in the evolution of mammals and has important academic significance will eventually decrease or become extinct as human economic activities increase further.