Marsupials & Rodents

I need some help, Animal Experts! I shot my mouth off this morning and stated that an animal couldn’t be a rodent and a marsupial at the same time. Now I’m wondering if I was right. I hate it when this happens. I need to learn to engage brain before mouth.

Also pandas aren’t related to bears and are more closely related to raccoons, right? I mean look at the lesser panda. Come on, tell me I at least know this one!

A marsupial cannot ever be a rodent, or vice-versa. Marsupials are a whole 'nother order than rodents.

And the giant panda used to be thought to be more closely related to raccoons than bears, but is currently classified with true bears.

Thanks jayjay! So, the one I thought might be shakey ground was right, and the one I thought I had down pat was wrong. Well, one out of two aint bad.

A small (hopefully) elaboration on taxonomy from an amateur (me):

Rodents belong to the Order Rodentia. Marsupials belong to the Order Marsupialia. They are both members of the Class Mammalia (mammals).


For instance, a house mouse is (in the above order) Animalia-Chordata-(Vertebrata)-Mammalia-Rodentia-Muridae-Mus-musculus.

A red kangaroo is Animalia-Chordata-(Vertebrata)-Mammalia-Marsupialia-Macropodidae-Macropus-rufus.

They’re identical up to the Order. Which means that a rodent cannot be a marsupial.

This is true. Rodents belong to the Order Rodentia, and are placental mammals, belonging to the subclass Eutheria. Marsupials used to be classed as the Order Marsupialia, but this is now usually broken up into several separate orders, and belong to a different subclass Metatheria. There are some marsupials which look like rodents of various kinds, but the similarity is purely convergent.

This is wrong. Recent evidence has pretty well established that Giant Pandas are bears, though rather odd ones. AFAIK, the jury is still out on the Lesser Panda.

I appear to be behind the times! :smack:

Thanks, Stoopit Roomate is claiming he saw some animal on Larry King Live last night that was both. I told him not possible. He couldn’t tell me the type of animal, (although he said the body looked like a chinchilla) so I couldn’t google it. I then decided to one up him, and made the panda comment. So maybe I’m the Stoopit Roomate for not keeping my mouth shut. Sigh…I coulda sworn my ZooKey from the Philadelphia Zoo made the box with the recording tell me pandas were not bears. Since it was over 30 years ago, it probably did tell me that. Maybe I need a new ZooKey.

Yeah, it was decided that putting all the pouchies in one bag was a bit of placental chauvinism. The marsupials were put into one order purely because they shared a form of reproduction, even though they differed among themselves nearly as much as placentals did. Although placentals also shared a form of reproduction, they were split into more than 20 orders.

Classifications vary, but this is one arrangement:

Superorder Ameridelphia

* Order Didelphimorphia (63 species)
      o Family Didelphidae: opossums
* Order Paucituberculata (6 species)
      o Family Caenolestidae: shrew opossums

Superorder Australidelphia

* Order Microbiotheria (1 species)
      o Family Microbiotheriidae: Monito del Monte
* Order Dasyuromorphia (63 species)
      o Family Thylacinidae: Thylacine extinct
      o Family Dasyuridae: antechinuses, quolls, dunnarts, Tasmanian Devil, and relatives
      o Family Myrmecobiidae: Numbat
* Order Peramelemorphia (21 species)
      o Family Peroryctidae rainforest bandicoots
      o Family Peramelidae: bandicoots and bilbies
* Order Notoryctemorphia (2 species)
      o Family Notoryctidae: marsupial moles
* Order Diprotodontia (117 species)
      o Family Phascolarctidae: Koala
      o Family Vombatidae: wombats
      o Family Phalangeridae: brushtail possums and cuscuses
      o Family Burramyidae: pygmy possums
      o Family Tarsipedidae: Honey Possum
      o Family Petauridae: Striped Possum, Leadbeater's Possum, Yellow-bellied Glider, Sugar Glider, Mahogany Glider, Squirrel Glider
      o Family Pseudocheiridae: ringtailed possums and relatives
      o Family Potoridae: potoroos, rat kangaroos, bettongs
      o Family Acrobatidae: Feathertail Glider
      o Family Hypsiprymnodontidae: Musky Rat Kangaroo
      o Family Macropodidae: kangaroos, wallabies, and relatives

Like I said, there are some kinds of marsupials that look like rodents, but aren’t. And there are lots of rodents that have pouches, but the pouches are in their cheeks for holding food. He probably misunderstood what was being said.

As previously stated, there are a number of marsupials convergent with placentals, however. And while it is not a rodent, the marsupial version of the “mouse,” is indeed called the “marsupial mouse.”

They act a lot more shrews, though, being highly carnivorous/insectivorous.

Here’s a transcript of last night’s Larry King Live. Jack Hanna was the guest, and there were a LOT of animals…I’m guessing your roommate got his wires crossed on the viscacha and the opossum.

My God, no wonder he got confused. What did they have, like 20 animals on the show?

Well, that, and speaking in shrill iambic pentameter. :cool:

Thanks again! I’m thinking you’re right. That viscacha has sort of a flat face, and he did mention that. I’m going to have to drag him in here later to see the lovely list of latin names since he didn’t believe my verbal report. Or maybe not…I wasn’t very nice and there isn’t any money riding on this. It’s just good to know that I was right about the rodent/marsupial thing. I thought they were different classifications but I wasn’t sure on what level.

I think I found the point where the roommate got confused. They’re talking about a viscacha here:

Okay. I’ve gone through the transcript and noted down the animals they showed.

bear cub
capuchin monkey
squirrel monkey
arctic fox
fennec fox
giant African bullfrog
poison dart frog
African porcupine
prairie dog
Patagonian cavy
hairy armadillo
Siberian lynx
red kangaroo
Bennett wallaby

They had THIRTY animals on the show last night. I’m not surprised in the least he was confused. With commercials, that means each one, if the times were balanced, got a very little less than a minute each.

OK, so I have to give him a break on this one. That is a lot of animals, pretty late at night, after a long day of cooking for tourists that come off of cruise ships. So I won’t say “neener neener neener” or anything like that. But I’ll still think it. He’s one of those guys who thinks he knows everything, but is actually usually wrong. I need to introduce him to Snopes and the Dope!

Or like Grasshopper Mice :).

  • Tamerlane

Is it not inconcievable that some of the similarity is preserved legacy from the common ancestor of marsupials and placentals, which might well have been a ‘ratty’ sort of thing?

Unlikely, since both the “marsupial rodents” and rodents themselves are derived members of their respective clades. That is, the earliest members of Eutheria may have looked “ratty”, but rats themselves are fairly derived eutherians. The ratty appearance of our forebears had more to do with them being small, furry tetrapods (and they all look the same to me) than with rats being primitive members of Eutheria. Similar to how all early reptiles looked “lizardy”, but true lacertilian lizards are derived, not primitive, reptiles.

The trait of being “small and furry” seems to have played a larger role in determining the form of rodents and rodent-like marsupials than did common ancestry.