Saturnalia (dinosaur)

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Saturnalia
Fossil range: Late Triassic

Kingdom:	Animalia
Phylum:	Chordata
Class:	Sauropsida
Superorder:	Dinosauria
Order:	Saurischia
Family:	Guaibasauridae
Genus:	Saturnalia Langer et al., 1999

Species

S. tupiniquim Langer et al., 1999 (type)

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. This may indicate Sauropodomorpha is not a natural grouping (polyphyletic).

1 Classification
2 Discovery and species
3 References
4 See also
5 External links

[edit] 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.^[1] 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.^[2]

Jose 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.^[3]

[edit] Discovery and species

The holotype was discovered in mid-winter at Sanga da Alemoa, Rio Grande do Sul, in Brazil, and additional remains were discovered during 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.

[edit] References

^ Langer, M.C., Abdala, F., Richter, M., and Benton, M. (1999). "A sauropodomorph dinosaur from the Upper Triassic (Carnian) of southern Brazil." Comptes Rendus de l'Académie des Sciences, 329: 511-;517.
^ Langer, M.C. (2003). "The pelvic and hind limb anatomy of the stem-sauropodomorph Saturnalia tupiniquim (Late Triassic, Brazil)." PaleoBios, 23(2): September 15, 2003.
^ Bonaparte, J.F., Brea, G., Schultz, C.L., and Martinelli, A.G. (2007). "A new specimen of Guaibasaurus candelariensis (basal Saurischia) from the Late Triassic Caturrita Formation of southern Brazil." Historical Biology, 19(1): 73-82.