As a general rule, most mammals grow and develop inside the mother’s womb. When they are born, the puppies are already well formed and able to adapt to a normal life. However, marsupials are mammals that do not fulfill this characteristic .
the kangaroo example
A baby kangaroo lives only five weeks in the mother’s womb. At birth, its size is very small, it lacks hair and cannot see.
As a result, it has to crawl from the birth orifice to the maternal pouch where the nipple is located. When it comes in contact with the nipple, it clings to it and the mother starts to produce milk. For several weeks, the puppy remains hanging from the nipple and thus begins to grow and develop. The pouch that the baby holds is known as a marsupial or marsupial pouch, it works as an external matrix that serves as shelter and protection.
Once the puppy is old enough, it will be able to jump out of the bag for a period of time. After ten months it gets too big to fit in the mother’s bag and finally abandons it.
Physiologically, female kangaroos differ from other mammals because of their reproductive system . It has two uteri, two independent vaginas and an underdeveloped placenta. On the other hand, the male’s penis is bifid at its tip and is located behind the scrotum.
Most marsupials live in Oceania
These animals come from Australia, Tasmania and New Guinea. Its size is quite variable, as some species are very small, while others are as big as a human being. Among the smaller ones, the Tasmanian devil and the marsupial anthill stand out. The biggest ones are the koala and the kangaroo.
The lesser-known species is the kangaroo rat (Potorous gilbertii), an animal believed to be totally extinct, but in the 1990s some living species were found.
As for koalas, they are in danger of extinction and their greatest threat is chlamydia, a disease that leaves them blind and causes infertility.
The possum is native to the American continent . Most of the day they live in trees and their diet is very varied. It is a slow and useless animal, but it is difficult to catch it because it knows how to camouflage itself and when it feels trapped it pretends to be dead.
Unlike other marsupials, it generates antipathy among humans, as it feeds on chickens and other farm animals.