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.
Achillobator
Achillobator ( ) is a dromaeosaurid theropod dinosaur that lived roughly 93 to 80 million years ago during the Late Cretaceous in what is now Mongolia, in Asia. It was among the largest dromaeosaurs; the holotype and only known individual of "Achillobator" is estimated at long. "Achillobator" was a moderately-built, ground-dwelling, bipedal carnivore. It would have been an active predator, hunting with the enlarged, sickle-shaped claw on the second toe.