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Why are plancetals more successful than marsupials and monotremes?
Wiki User
∙ 7y ago
Because placentals are the largest number of mammals.
Wiki User
∙ 13y ago
Wiki User
∙ 14y agomonotremes lay eggs
placentals young are nourished before birth in the placenta
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Are echidnas marsupials?
No, echidnas are not marsupials. They are monotremes, that is, egg-laying mammals. However, during breeding season, the female does develop a rudimentary pouch in which she incubates her egg, but this is really nothing more than a flap of skin.
Are chiropterans placentals marsupials or monotremes?
Marsupials, monotremes and placental mammals are all sub-groups of mammals. They share the following characteristics:vertebrateswarm-bloodedhave fur, skin or hairbreathe through lungs (not gills)the young feed on mother's milkThe major differences, however, include:monotremes are the only mammals which lay eggsmarsupial young are born undeveloped and continue most of their growth and development whilst they are in the mother's pouch, attached firmly to the teat for several months, where they receive all their nutrients.
What is the reproduction of placentals marsupials and monotremes?
All three groups of mammals copulate. Male monotremes and marsupials have split penises with two functional heads (male monotremes also have two non-functional heads). They are used only for reproduction, as they urinate through the cloaca. Placental mammals have a single-headed penis that it used for both urination and reproduction. If the egg is fertilized, the embryo develops in the female's uterus. In monotremes, an eggshell forms around the embryo, and the female lays the egg, out of which the baby hatches. Marsupials give live birth, but the young are delivered prematurely. They must crawl up to the nipple (often inside a pouch) and attach to it. They do not detach for the first time until they are more fully developed. With the help of a more advanced placenta inside the uterus (marsupials have simpler placentas), placental mammals give live birth to more advanced young after a much longer gestation period. Female monotremes produce milk, but it simply passes through the skin; they have no nipples. Female marsupials and placental mammals have nipples, from which the babies suckle.
How do placental monotremes and marsuprials differ?
Placental mammals give birth to live young, which, during development, are nourished by a placenta. Marsupials give birth to very tiny, undeveloped offspring, which they then shelter in a pouch until the baby has developed more fully. Monotremes are mammals that lay eggs, and the only existing types are the platypus and the echidna.
How many eggs do opossums lay?
True anteaters do not lay eggs.True anteaters should not be confused with "Spiny anteaters", more properly known as echidnas. These creatures are monotremes, meaning that they are egg-laying mammals, like platypuses.
What are types of mammals?
They are:1. Monotremes - They are animals that lay eggs and the young suckle mother's milkafter hatching.2. Marsupials - Nursing young housed in external pouch and embryo are nursedinside the mother by placenta.3. Eutherians - Placenta provide more intimate and long lasting associationbetween the mother and developing young.
Are Tasmanian tigers monotremes?
No. The now-extinct Tasmanian Tiger, more properly known as the Thylacine, was a marsupial. The only known monotremes are platypuses and echidnas.
Does South America has the largest number and variety of Marsupial mammals?
No. Australia and nearby islands have more marsupials than South America. Also, Australian marsupials are more varied; almost all South American marsupials are opossums.
Do monotrems have mammary glands?
Yes. Monotremes are mammals, so they have mammary glands. What they lack, however, is developed teats for the young babies to suckle. These animals do not suckle their young quite like other mammals do. They do not have nipples, but exude milk from specialised sweat glands on their abdomen.
How did marsupials get their name?
Marsupials essentially got their name from the fact that the proper name for a marsupial's pouch is marsupium. Most (not all) marsupials have such a pouch. Some marsupials have nothing more than a flap of skin which helps secure the developing joey in place.
Are the spiny anteater and platypus amphibians?
The "spiny anteater" is only a nickname for echidna. Echidnas and platypuses are monotremes which means egg laying mammals.
Why does the Australian continent have animal life that is not found anywhere else?
It's been long isolated, so species found niches there which weren't coveted by more adaptive animals. Even so, the monotremes (echidnas and platypuses) are just hanging on and some marsupials, notably the thylacine, have lost out to their placental counterparts (in that case, the dog).
