Dinosaur size
There were larger dinosaurs, but knowledge of them is based entirely on a small number of fragmentary fossils. Most of the largest herbivorous specimens on record were discovered in the 1970s or later, and include the massive titanosaur "Argentinosaurus huinculensis", which is the largest dinosaur known from uncontroversial evidence, estimated to have been and long. Some of the longest sauropods were those with exceptionally long, whip-like tails, such as the "Diplodocus hallorum" (formerly "Seismosaurus") and the 33- to 35-metre-long (108–115 ft) "Supersaurus". The tallest was the "Brachiosaurus".
Earl Douglass
Douglass played a central role in one of the most important fossil finds in North America. In 1905, he was sent to Minnesota, North Dakota, Montana, and Idaho to collect vertebrate and invertebrate fossils. Additionally, he obtained data to solve certain geological problems and conduct geological explorations. In 1907, Douglass traveled to the Uintah Basin in northeastern Utah to explore fossiliferous strata. Later in 1908, he explored the hills along the Green River near Jensen, Utah and came upon with the tail section of an Apatasaurus in the Morrison Formation. The following year while searching fossils for the Carnegie Museum, he discovered a formation layered with prehistoric plant and animal fossils. In the summer of 1909, Earl traveled to Utah to search for dinosaur skeletons , where he discovered his famous dinosaur at the Utah quarry. The dinosaur was formally named "Apatosaurus louisae", after Carnegie’s wife Louise. In the same year, while climbing the Split Mountain near Jenson, Utah he found eight large vertebrae partially embedded in the rock, which turned out to be the entire body of a brontosaur nearly 70 feet long.