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.
Giraffatitan
Between 1914 and the 1990s, "Giraffatitan" was claimed to be the largest dinosaur known, (ignoring the possibly larger but lost "Amphicoelias") and thus the largest land animal in history. In the later part of the twentieth century several giant titanosaurians found appear to have surpassed "Giraffatitan" in terms of sheer mass. However, "Giraffatitan" and "Brachiosaurus" are still the largest brachiosaurid sauropods known from relatively complete material.