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.
History of paleontology in the United States
By the beginning of the 19th, their fossil footprints definitely had. Later in the century as more dinosaur fossils were uncovered eminent paleontologists Edward Drinker Cope and Othniel Charles Marsh were embroiled in a bitter rivalry to collect the most fossils and name the most new prehistoric species. Early in the 20th century major finds continued, like the Ice Age mammals of the La Brea Tar Pits, the Oligocene bonebeds of South Dakota, and the Triassic bonebeds of New Mexico. Mid-to-late twentieth century discoveries in the United States triggered the Dinosaur Renaissance as the discovery of the bird-like "Deinonychus" overturned misguided notions of dinosaurs as plodding lizard-like animals, cemented their sophisticated physiology and relationship with birds. Other notable finds include "Maiasaura", which provided early evidence for parental care in dinosaurs and ""Seismosaurus"" the largest known dinosaur.