Yellow Spotted Hyrax
Fairy Armadillo
Tree Pangolins
I don't believe I have herd of these species in Zoological Captivity-
Olingos
There was a Fairy Armadillo briefly at Cotswold Wildlife Park in quite recent times, but I've never met anyone (staff excepted) who saw it. It was on a historic stock list that was shown at a zoo history event there a few years ago.
Wow, that's astounding. Sorry for sounding a little cynical but was that a positive identification? As far as I can think I can't remember Cotswold having particularly strong ties to the US and wonder if it could be a typo (the "H" is not far from an "F" on a keyboard).
I don't doubt your reporting, it just sound so incredulous.
No, it's fair call to be skeptical!
Its list entry was accompanied by scientific name and as I recall was discussed with staff from the zoo at the meeting. But as I say, I never saw the animal for final confimation, and this is from memory, so I may have some details wrong. It caused quite a stir, though!
You can find Mountain Nyala's in several German zoo's, as the FZS (Frankfurt Zoological Society) organizes and supports most of the projects in Ethiopia and Congo. And true, I forgot about the Mountain Gorilla's which die in captivity due to their specialized diet! Even though Antwerp zoo (Belgium) used to have the only captive female of the eastern Mountain Gorilla in the world. I'm not sure if they still have her, she was already quite aged when I saw her about 8 years ago.
Mountain Gorillas were kept in Cologne Zoological garden in a bad small cage.