This is an old theory that is no longer supported by most paleontologists AFAIK. Trunks require specific musculature, more blood vessels, and more nerves than a regular nose does, and those things leave evidence in the structure of the facial bones.

Snuffleupagus.

“Every reconstruction involves some level of inference and speculation to literally ‘flesh out’ details not preserved in the fossil record,” Celeskey explains. “In the process of creating paleoart, artists and the researchers have discussions about how to fill in these missing pieces, which helps everyone involved to think about how they are interpreting the actual evidence at hand.” From a NatGeo article I found

Nope, sauropods were already right up against the limit of what’s physically possible for a land animal on Earth. If they were that chonky they would have been too heavy and would have overheated just from their body heat.

Of course it’s possible. It’s highly improbable due to weight, of course, but it’s not impossible.

There’s a lot of information that was not recorded in fossil, and we have very few fossil recorded, compared to how many animals of a species lived. How we reconstruct existinct animals keeps on changing with every new information, so it’s always cool to challenge the way we view a creature.

Not very likely due to the weight. Same with the trunk suggestion, there was a lot of air space and gaps in the few skulls that were preserved to make them weight less.