To be perfectly honest, I haven’t specifically researched this answer - but I am still pretty sure I can say the answer is ‘no’. Here’s why:

Marsupials are mammals - which means they have mammary glands that produce milk, and they suckle their young on this milk.

Within the group of animals known as “mammals”, there are 3 kinds: marsupials, placentals and monotremes.

The marsupials have a “marsupium”, which is another name for a pouch. You know this - baby kangaroos, called joeys, often peer out from their mother’s pouch, which is on the mother’s belly. (Dad kangaroos don’t have pouches).

What happens is that the marsupial is born ultra-small - like the size of a jellybean. They crawl from the mother’s vagina, up through the fur on her front, and down into the pouch. Inside the pouch they locate a nipple and begin suckling. They derive their nutrition through the mother’s milk this way and continue to develop and grow until they are large enough to let go of the nipple and leave the pouch.

The placentals have a “placenta”. This is an organ that is formed within the womb when the mother is pregnant. The placenta is attached to the wall of the mother’s womb and is a bit like a sac or bag. It has a cord running from it to the young animal’s stomach - it connects to the stomach through the belly button.

The young animal gets its nutrition via the umbilical cord and continues to develop and grow within its mother’s womb until it is large enough to be born - certainly much larger than the jellybean-sized marsupials!

Here is an illustration (from what-when-how.com) of a human baby showing the placenta on the wall of the mother’s womb, the umbilical cord, and how the umbilical cord attaches to the baby at the stomach - this is where the bellybutton will form.

Finally, the monotremes lay eggs. The word monotreme relates to their reproductive system also and essentially means they have one (mono) opening (trema) for birth, urination and defecation. There are only a few monotremes - the platypus and echidnas. Eggs are laid in a burrow, hatch, and then the young animals suckle on milk produced from glands on the mother’s front.

By understanding the different ways that these three groups of mammals reproduce, we can see that only the placentals should have belly buttons - because the belly button is formed after birth, when the umbilical cord detaches from the infant’s stomach.

Neither the marsupials nor the monotremes make use of an umbilical cord in this way and so should not have belly buttons.

My favourite marsupial is the Tasmanian tiger - dog-like in form, with tiger-like stripes, and yet it was (or is) a marsupial! Females have pouches that “face backwards” (open from behind) so that as they move forward through scrubby bush, no leaves, twigs and branches and so on accidentally enter the pouch.

Here is a photo of a Tasmanian tiger walking away from the camera - you can see its belly region hanging low as it has a full pouch.

Find out more about Tasmanian tigers at my website Where Light Meets Dark or follow along on Facebook Where Light Meets Dark.