I wish really big rhinoceros was still around. I would have liked to have seen a herd at browse. Or just listened to the thump-thump-thump of their feet as they wandered about.
We could put a few, perhaps a couple of cows and their babies and maybe one large bull, right out there in the back field. But how would we fence them? Or feed them, after they'd stripped the birches and the oaks? How many truckloads of hay does an adult paraceratherium eat in a day? What size barn would we need to house them during the long winter months?
On the whole, I am forced to admit that although picturesque, paraceratherium would be a very expensive, inconvenient pet.
And then there's the scat. Contemporary rhinocerotes are famous for making "communal dung piles." Did their ancestors also do so? I can imagine some truly formidable foothill-size formations.