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.
Evolution of dinosaurs
The earliest confirmed dinosaur fossils include saurischian ('lizard-hipped') dinosaurs "Nyasasaurus" 243 Ma, "Saturnalia" 225-232 Ma, "Herrerasaurus" 220-230 Ma, "Staurikosaurus" possibly 225-230 Ma, "Eoraptor" 220-230 Ma and "Alwalkeria" 220-230 Ma. "Saturnalia" may be a basal saurischian or a prosauropod. The others are basal saurischians.