Sauroposeidon
The press release in 1999 immediately garnered international media attention, which led to many (inaccurate) news reports of "the largest dinosaur ever!". While "Sauroposeidon" likely represents the tallest known dinosaur taxon, it does not hold records for either the longest or most massive. "Patagotitan" or "Argentinosaurus" make better candidates for the title "World's Largest Dinosaur" (presuming to ignore, as is conventional, "Amphicoelias"), though incomplete fossil evidence makes exact rankings impossible.
Puertasaurus
"Puertasaurus" was a very large animal. Its size is difficult to estimate due of the scarcity of its remains, but modern estimates place it around long and in mass. The largest of the four preserved bones is the dorsal vertebra, which at wide is the broadest known vertebra of any sauropod. The Cerro Fortaleza Formation is of uncertain age, due to the inconsistency of stratigraphic nomenclature in Patagonia. When "Puertasaurus" was alive, the Cerro Fortaleza Formation would have been a humid, forested landscape. "Puertasaurus" would have shared its habitat with other dinosaurs, including another large sauropod, "Dreadnoughtus", in addition to other reptiles and fish.