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.
Alamosaurus
"Alamosaurus" was a gigantic quadrupedal herbivore with a long neck and tail and relatively long limbs. Its body was at least partly covered in bony armor.The total length of "Alamosaurus" is estimated to be long. Though most of the complete remains come from juvenile or small adult specimens, three fragmentary specimens, SMP VP−1625, SMP VP−1850 and SMP VP−2104, suggest that adult "Alamosaurus" could have grown to enormous sizes comparable to the largest known dinosaurs like "Argentinosaurus", which has been estimated to weigh . Scott Hartman estimates "Alamosaurus" being slightly shorter at and is equal in weight to other massive titanosaurs such as "Argentinosaurus" and "Puertasaurus". However, he says that at the moment, scientists do not know whether the massive tibia belongs to an "Alamosaurus" or a completely new species of sauropod.
Though no skull has ever been found, rod-shaped teeth have been found with "Alamosaurus" skeletons and probably belonged to this dinosaur. The vertebrae from the middle part of its tail had elongated centra. "Alamosaurus" had vertebral lateral fossae that resembled shallow depressions. Fossae that similarly resemble shallow depressions are known from "Saltasaurus", "Malawisaurus", "Aeolosaurus", and "Gondwanatitan". "Venenosaurus" also had depression-like fossae, but its "depressions" penetrated deeper into the vertebrae, were divided into two chambers, and extend farther into the vertebral columns. "Alamosaurus" had more robust radii than "Venenosaurus".