I don’t think anyone has survived a solid hit at terminal velocity. They either hit the side of a hill, were slowed by branches, landed in soft ground, etc. A person falling on a flat stretch of grass is definitely deadzo.
I’ll grant that you need fortuitous circumstances of some sort or another (hillside, snow, etc.), but most of the discussion (including the OP) doesn’t specify conditions, so the limit should arguably be taken to be assuming optimal conditions.
I too, was worried to distraction that so called, ‘Scientists’ were hucking housecats, cape buffaloes, and octopi off of balconies in the name of science. The need for such research is obvious; it just bothered me that they might be doing so without strict controls in place.
Many, many humans have survived falls at terminal velocity – when their mass is added to that of an open parachute.
Wouldn’t that depend on the shape and material of the bag? Surely a fairly rigid bag made of an airtight material would have the same terminal velocity no matter what it was filled with to bring the total weight to 1 lb.
I’m with psychonaut… one pound is one pound, right? I understand that friction from air resistance will have an effect on speed, if the sizes/shapes are different. But I think if those factors (size and shape) are equivalent, shouldn’t the speed (velocity) be, also? 
Currently for my doctorate, I’m writing a thesis on whether the flesh of babies, puppies or kittens tastes better when fried in olive oil.
Let us know your results:p
But there’s no way the two would be the same size and shape, as buckshot is denser than feathers, and anything called a bag changes shape somewhat based on its contents.
Exactly. Try stuffing a pound of feathers into the same size bag as a pound of lead shot. It’s not going to work. (And even if you use a bigger bag in both cases, the “emptier” one containing the lead will behave differently in freefall than a full one.
As for animals and falls, my wife (20 years ago or so) observed empirically, and I should add accidentally, that a gerbil will not survive a fall from the shoulder of a child
onto a tiled kitchen floor. 
Hmm, I thought I remembered posting that before. See earlier thread (along with other data points suggesting gerbils can and do survive falls from shoulder height).
Sure they would. Take two thick leather bags which each weigh a pound less a gram. Put one gram of lead shot in one and one gram of feathers in the other. Now you have, as the original poster of this scenario specified, a one-pound bag of lead shot and a one-pound bag of feathers. I very much doubt that the one gram of lead shot is going to deform the leather sufficiently to make any measurable difference in its bag’s terminal velocity vis-à-vis the feather bag.
Even if the original poster really meant to specify bags filled with one pound of lead shot and feathers, respectively, then my argument still applies provided you use bags which are thick and heavy enough.
I disagree. Under optimal conditions any animal is going to survive a fall at terminal velocity. It makes more sense to assume a normal definition of ground, without
unusual circumstances.
True, but you’re going to need to be a lot more optimum than a snowy hillside (something which does, after all, occur fairly often naturally) to accommodate an elephant.
There’s this cat, who survived a 12-story fall. (FYI, the youtube links for the search terms I used are confusingly disturbing).
I actually heard the noise in my mind while reading that.