Australia is considered the kingdom of marsupials, home to cuddly koalas, furry kangaroos, and adorable wombats. Since the continent has so many marsupials, you may wonder, are there marsupials outside of Australia?
Well, the answer may surprise you. Before they made it to Australia, marsupials had been around for at least 70 million years.
When compared with other mammals, marsupials are considered to be odd.
Dissimilar from placental mammals, including whales, dogs, and even humans, marsupials give birth to somewhat underdeveloped young that continues to grow in their mother’s pouch.
With all this in mind, we will explore whether or not there are marsupials outside of Australia and where they first originated from, too.
Let’s get straight into it!
Can You Find Marsupials Outside Of Australia?
When looking at marsupials, there are over 330 species – two-thirds of these inhabit Australia. However, the other third mostly live in South America. These include the opossum and the yapok.
Where Did Marsupials Originate?
Contrary to popular belief, marsupials didn’t originate in Australia, instead, the oldest known marsupials are from North America.
It was here where they evolved during the Cretaceous period after removing themselves from the placental mammals approximately 125 million years ago.
These ancient marsupials appeared to thrive in North America, populating what used to be known as the supercontinent Laurasia with about 15 to 20 species of marsupials. However, these are now extinct.
The reason why these marsupials decided to travel toward South America – which was around the same time as the extinction of the nonavian dinosaurs – is unclear.
Keep in mind, during this time, North and South America weren’t connected as they are today.
However, they were close together, and a series of islands or land bridges may have linked them. This connection provided a range of animals with the ability to expand their ground.
After their arrival in South America, the marsupials and their relatives began to diversify like crazy. With animals that we know today as a weasel- and bear-sized carnivores, some featuring saber teeth. Other marsupials evolved to eat seeds and fruits.
Between then and now, many of these marsupials went extinct; however, South America remains a hotspot for these animals.
In South America, there are over 100 species of opossums, 7 different species of shrew opossums, and an incredibly cute monito del monte (Dromiciops Gliroides), whose names mean ‘little monkey of the mountain’ when translated from Spanish.
Moreover, in the last 1 million years, one of the opossums found in South America traveled north and now resides in North America.
This is known as the Virginia opossum (Didelphis virginiana) – this is the only marsupial found in the north of Mexico.
Likewise, while opossums and possums may sound similar, they are both from a different order. Possums are native to New Guinea and Australia – close relative to the kangaroos! – and have different anatomical differences.
For one, they have enlarged lower incisors as opposed to their South American counterparts.
How Did Marsupials Get To Australia?
Around 35 to 40 million years ago, both Australia and South America were linked to Antarctica, and the result was a giant mass of land.
However, during this time, Antarctica wasn’t what we knew it as today: covered in ice. Instead, you could find a temperate rainforest.
As such, it could be presumed that the marsupials, along with their relatives, were transported from South America and hopped straight into Antarctica where they eventually found Australia.
This doesn’t have to be presumed, either, there is fossil evidence!
This can be found on the Antarctic’s Seymour Island where there are fossil remains of marsupials and their relatives, including close relatives to the monito del monte.
The oldest found marsupial fossil was discovered at a 55-million-year-old site in Australia called Tingamarra, close to the town classed Murgon located in Queensland. Some of the fossils found here are similar to those found in South America.
An example of this would be the tiny and ancient fruit-eating marsupial known as the Chulpasia that originated in Peru, which is a close relative to another marsupial whose remains were found at Tingemarra.
Another marsupial found in Tingamarra, the Djarthia – an insect-eating animal, could be considered another ancestor of the living marsupials found in Australia.
However, there is a large gap in the records of Australian fossils. After the discovery of Tingamarra, the second oldest recorded marsupial fossils are 25 million years old.
This is the result of a huge amount of diversification found in Australia.
With the introduction of koalas, you’re also seeing relatives of wombats and bandicoots – essentially all the major Australian marsupial groups that could be found during this period.
As previously stated, it is unclear why marsupials thrived on the lands of Australia.
One idea counters that when times were hard, marsupial mothers were able to jettison any developing young they had in their pouches, whereas mammals were required to wait until gestation was finished, this caused them to spend essential resources on their offspring.
Another idea surrounds the concept that there were no other placental mammals in Australia competing with the marsupials. However, since then, this idea has been contradicted. This was showcased in the form of a fossil tooth.
This was considered to belong to a placental-mammal or relative uncovered during the Tingammar discovery. This highlights that placental mammals were, in fact, present on the continent as far back as 55 million years ago.
In today’s Australia, there are roughly 250 marsupial species, and in South America, there are approximately 120 marsupial species, with one living in North America – Virginia opossum.
What we have understood from this section is the ancestral geography of marsupials has essentially been flipped. We are seeing a completely different pattern from one 125 million years ago.
Are There Marsupials In South America?
As previously mentioned, all living marsupials – this includes opossums, wallabies, and kangaroos – originated in South America.
However, marsupials – mammals known for keeping their offspring in the belly poaches of their females – can still be found in South America, too.
Below, we will outline some marsupials found in South America.
This eastern caenolestid makes up one of seven species known as the shrew opossum. As their name suggests, these tiny, shrew-like marsupials are from the Caenolestidae family.
They can be found on and around the Andes in South America. These are thought to have branched off from the other marsupials during evolution.
Their scientific name – Caenolestes sangay, takes reference from the active volcano in Ecuador, the Sangay. The tiny eastern caenolestid was first found in the Sangay National Park. Here, you can find both the Sangay volcano and the Tungurahua.
While many people believe marsupials to have originated in Australia, this is simply not the case.
Instead, millions of years ago, they could be found in South America and even North America – where some still remain to this day. For instance, the Virginian opposum.
Hopefully, this guide has informed you whether or not there are marsupials located outside of Australia(see also: Why Are There So Many Marsupials In Australia?).