I sat down to write about a new marsupial that was found in South America. I wanted to check some facts before I wrote, and I’m glad I did because I was wrong about some basic things. Here are some things I thought I knew…
1) Marsupials come from Australia, except for the Opossum.
I was wrong about this, but not too surprised. Marsupials actually come from South America. The ones in Australia got their from South America when the two land masses were attached. While marsupials thrived in Australia, they faced competition from placental mammals in South America and thus they’re an “also ran” rather than what one associates with the place.
Opossums are the only marsupial found in North America, so I got that part right. And I knew that the animal called “possum” in Australia was not closely related to the opossum, which is also called “possum” in the US.
2) There are no native marsupials except in Australia and North America
I was really sure I was right on this, but no. There are native marsupials in Australia, South America, Central America, North America, New Guinea, Borneo, and other nearby islands. There’s an interesting feature called The Wallace Line that separates Australian animals from Southeast Asia’s animals. I should probably do a separate piece on that.
So while 70% of the world’s marsupial species live in Australia, a full 30% live elsewhere.
3) Monotremes are not marsupials.
True! Monotremes are the egg-laying mammals, including the echidna and the platypus. I found a few sources that said they were a suborder of marsupials, which surprised me. A deeper look shows that they’re not considered marsupials at all. They’re in the same class (mammalia), but that’s as close as they get. That’s a close as we get too.
So I got one thing right out of three. Is that good? Bad? I don’t care. What I really got was a whole bunch of new information about the dozens of species of South American marsupials. They’ve got fishing opossums, tiny mouse-like opossums, and several species of four-eyed opossum, so-named because of the white spot above each eye. And they’ve got the new one, the Monito del monte, which means “little monkey of the mountains.”
While it’s not much news to biologists that there’s a marsupial in South America, this find is a big deal. This critter is the only known representative of the order Microbiotheria. And it’s cute. If you can imagine a tiny cross between a monkey, a mouse and a koala, you’ve got a pretty good idea about these guys. Give “Monito del monte” a Google if you’d like to know more.
As for me, I’m always glad to learn I was wrong about something like this. As of today, my world is a bigger, more wondrous place. And it has tiny mountain monkey mice in it.