Saturnalia

Saturnalia is a genus of very early saurischian dinosaur, from the Carnian faunal stage of the late Triassic period (227.4 to 220.7 million years ago), making it one of the oldest true dinosaurs yet found. It may have been a primitive sauropodomorph, a group which includes the giant sauropods. It probably grew to about 1.5 meters (5 ft) long. The few known remains of this genus have many prosauropod features, yet lack other characteristics shared by all dinosaurs.

Classification
The primitive nature of Saturnalia, combined with its mixture of sauropodomorph and theropod characteristics, has made it difficult to classify. Paleontologist Max Cardoso Langer and colleagues, in their 1999 description of the genus, assigned it to the Sauropodomorpha. However, in a 2003 paper, Langer noted that features of its skull and hand were more similar to the sister group of sauropodomorphs, the theropods, and that Saturnalia could at best be considered a member of the sauropodomorph "stem-lineage", rather than a true member of that group.

José Bonaparte and colleagues, in a 2007 study, found Saturnalia to be very similar to the primitive saurischian Guaibasaurus. Bonaparte placed the two in the same family, Guaibasauridae. Like Langer, Bonaparte found that these forms may have been primitive sauropodomorphs, or an assemblage of forms close to the common ancestor of the sauropodomorphs and theropods. Overall, Bonaparte found that both Saturnalia and Guaibasaurus were more theropod-like than prosauropod-like.

Discovery and species
The holotype was discovered in mid-summer at Sanga da Alemoa, Rio Grande do Sul, in Brazil, in the geopark of Paleorrota, and additional remains were discovered during the Carnival, which is believed to have its origins in the Roman winter solstice festival, Saturnalia; after which it was named in 1999, along with a Portuguese/Guarani word meaning native. The partial skeleton and referred remains from two other specimens including a jaw and teeth have also been discovered.