I was trying to find some info on naked mole rats to win an argument and found some references to the “Delicate Slender Opossum” being a social animal. I found an article that says they live in nests underground and raise mushrooms and insects. I visit a few sites that frequently have “weird science”-type articles and this is the first I heard about this.
It’s complete bullshit. The species Marmosops parvidens exists, and is quite widely distributed in northern South America, but is not known to have the kind of social structure described. That would be so extraordinary for a mammal that it would be front-page news in every science journal in the country, and I can’t find any links besides those you give (and others similar). Since the article cites no publications, I have no doubt it’s a hoax.
I found it anyway, though. Interesting. I checked the history and it seems that this article was on Wikipedia for just three days, yet has been copied and referenced in many other places.