Supersaurus

Supersaurus (meaning "super lizard") is a genus of diplodocid sauropod dinosaur that lived in North America during the Late Jurassic period. The type species, S. vivianae, was first discovered by Vivian Jones of Delta, Colorado, in the middle Morrison Formation of Colorado in 1972. The fossil remains came from the Brushy Basin Member of the formation, dating between 153 and 145 million years ago. It is among the longest dinosaurs ever discovered, with the three known specimens reaching in length, with the largest individual possibly exceeding in size. Mass estimates for the WDC and BYU specimens tend to be around in body mass. A potential second species, S. lourinhanensis (Dinheirosaurus), is known from Portugal and has been dated to a similar time.

==Discovery== left|thumb|James A. Jensen with the reconstructed front leg of Ultrasauros Supersaurus is present in stratigraphic zone 5 of the Morrison, dating from the Tithonian. The original fossil remains of Supersaurus were discovered in the Dry Mesa Quarry in 1972. This find yielded only a few bones: mainly the shoulder girdle, an ischium, and tail vertebrae. Paleontologist James A. Jensen described Supersaurus; he designated a scapulocoracoid BYU 9025 (originally labeled as BYU 5500) as the type specimen. This shoulder girdle stood some tall, if placed on end. The specimen was given the name "Supersaurus" informally as early as 1973, but was not officially described and named until more than a decade later, in 1985. Sauropod researcher Jack McIntosh at one time thought that the BYU Supersaurus material might represent a large species of Barosaurus but later felt that there was evidence for Supersaurus being a valid genus.