My little cocker spaniel weighs 42 lbs, so 40-50 lbs isn't that big at all.
I saw a hybrid thing a few months ago near my home in South Carolina, still not sure what I saw exactly. As I rounded a curve and down a hill there was an animal just to the left of the yellow line. It was sitting on its haunches like you'd expect a squirrel to sit. As I came down the hill, in broad daylight with a cloudless sky, I thought "that's a squirrel, nope a cat, nope a squirrel." It's hard to describe the animal I saw. It wasn't a squirrel, rat, cat or racoon. I grew up here when this was still country, and this particular animal I'd never seen or heard of before.
We're always discovering the yet undiscovered plant/animal life. It's not unlikely that some of these new discoveries are right under our noses and we don't recognize them.