Why are marsupials and monotremes unique to Australia?

Show all answers

Ross M

Monotremes are not marsupials they are a distinct subgroup of mammal and contain only the echidna and platypus.
The platypus is unique only to Australia but the echidna can also be found on the island of New Guinea so they also exist in Papua New Guinea and Indonesia.

There are a few species of marsupials in the Americas such as the opossum, but the vast bulk of the family are in Australia (and new Guinea)

South America used to be a strong hold of marsupials but when the land bridge to Nth America opened up more advanced placental mammals migrated south and out competed the indigenous marsupials. Australia's isolation prevented this from happening historically

WhatAmI?

Continental Drift. What became Australia broke away from Pangaea when mammals were still quite primitive and marsupial. There were no placental ancestors in Australia when it broke away and never developed there. Placental mammals are "newer" and developed after Australia became isolated from the rest of the world.

The reason why there are virtually no marsupials in the rest of the world is because placentals out competed them and the marsupials died off.

Opossums are the only marsupial in North America.

oceangirl78

Early in geological history, Australia was cut off from the rest of the world's land masses. This allowed a range of animals to establish successful populations in Australia - animals that were unable to do so in other parts of the world.

Australian marsupials include: koalas,Tasmanian devil,kangaroos,the bilby; the wallaby; the phascogale; the possum; the wallaroo; the glider; the bandicoot; the pademelon; the bettong; and the quoll

Almost all of Australia's native mammals are marsupials. Marsupials give birth to their young and then carry them in a pouch near their belly until the infant is old enough to survive on its own.

Another unusual type of mammal is the monotreme. Monotremes lay eggs instead of giving birth to live young. There are only two types of monotreme in the world - the platypus and the echidna - and both of them are found in Australia.

EDIT: It is true that marsupials can be found in other continents but they are predominantly here in Australia.

Anon Ymous

Marsupials are all over the world but 75% or 90% (i cant remember which one) of em live in Australia. The rest are in untouched jungles in PNG and the Amazon. I believe its because of geographic speciation and that there was little environmental destruction in Australia and Amazon. Everywhere else humans destroyed everything including the marsupials' habitat.

As for monotremes (who are just marsupials who lay eggs -> echidnas and platypuses) i think its just the environment thing and environment isolation.

Louie C

marsupials aren't actual unique to aus you can find them in south America(not the same ones but yeah) but i'd say because aus wasn't seen by people for millions of years (cept the aborigines) they weren't hunted and killed and made extinct. and they were able to evolve without interference by people. There are 3 types of monotreme the platypus. short-beak echidna and long-beaked echindna

Random info::They found a fossil of a monotreme from like the dino ages

Soph

you should look it up but I will tell you in short that it is because when the continents separated they were left to evolve only on Australia. I'm not sure of the details but really look it up its interesting stuff.

zafir

Monotremes are unique to Australia and New Guinea.

Marsupials are not unique to Australia, but most of the 140 species of Australian marsupials are not found anywhere else in the world.

It's believed marsupials evolved in North America, found their way to South America, and then into Australia via Antarctica when the southern continents were joined as Gondwana. In Australia they diversified to fill many niches.
the 140 uniquely Australian marsupials include:

Kangaroos
Wallabies
Bilbies
Possums and Gliders (several types only found here)
Numbats
Bandicoots
Koalas.

There are only two Monotremes in the world, the Platypus and the Echinda. The Platypus is unique to Australia, but there are four types of Echidna: the short-nosed Echidna is unique to Australia; the other three varieties are found in New Guinea.

EDIT: Smadarebna is correct! There are many species of marsupials living in other countries and continents. Possums are common in North America; and Papua New Guinea is home to species of kangaroo and koala, to name a few.

jboogie

idk...migration

Tommyy

cause no where else is cool enough for kangaroos.

smadarebma

They are not. Monotremes are because the only two members are platypus and echidnas. As for marsupials they are present on many continents.

Edit: You can give me a thumbs down if you care to but my answer is accurate. Marsupials live in forests, plains, and deserts. They are found in the Americas, Australia, New Guinea, and some neighboring islands. They include kangaroos, koalas, wallabies, wombats, bandicoots, and opossums. And monotremes were also not always indigenous to Australia as fossils have been found as far away as Argentina.

So as I said before....sorry not unique to you.

Enter Your Message or Comment

User Name:
User Email:
Post a comment: