Saturnalia tupiniquim

Saturnalia tupiniquim
Temporal range: Late Triassic, 233.23 Ma
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Skeletal reconstruction showing known remains of all specimens
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: †Sauropodomorpha
Family: †Saturnaliidae
Genus: †Saturnalia
Langer et al., 1999
Species:
†S. tupiniquim
Binomial name
†Saturnalia tupiniquim
Langer et al., 1999

Saturnalia is an extinct genus of basal sauropodomorph dinosaur known from the Late Triassic Santa Maria Formation of Rio Grande do Sul, southern Brazil. It contains one species, Saturnalia tupiniquim. It is one of the earliest known dinosaurs.

Discovery and naming

Fossils of Saturnalia were first collected by the Museum of Science and Technology of the Pontifical Catholic University of Rio Grande do Sul in the austral summer of 1998.[1] Some of the specimens were collected during Carnival.[2] The specimens were found at a site called Wald Sanga or Sanga do Mato, one of several sites called "sangas" in the vicinity of Santa Maria, Rio Grande do Sul, where red, fossil-bearing mudstone is exposed.[3]

Model showing outdated quadrupedal posture, Museu Nacional, Rio de Janeiro

In 1999, Max Cardoso Langer, Fernando Abdala, Martha Richter, and Michael J. Benton described the new genus and species Saturnalia tupiniquim based on the three skeletons.[2] The genus name is derived from the Roman festival of Saturnalia, in reference to the specimens' discovery during the festival of Carnival,[2] and the species name, tupiniquim, is a word of Guarani origin colloquially used in Portuguese to refer to things of Brazilian origin.[2][4]

Saturnalia tupiniquim is known from three well-preserved partial skeletons. The holotype, MCP 3844-PV is a partial skeleton including most of the presacral vertebrae and sacrum, the pectoral and pelvic girdles, the right humerus and part of the right ulna, the left femur, and most of the right hind limb.[2] The paratypes are MCP 3845-PV, a partial skeleton including a partial skull,[5] trunk vertebrae, pectoral girdle, right side of the pelvic girdle, right humerus, and most of the right hind limb, and MCP 3846-PV, a partial skeleton including trunk vertebrae, a tibia, and part of the foot.[2]

These fossils come from the Alemoa Member of the Santa Maria Formation, and are included in the Hyperodapedon Assemblage Zone.[3] A maximum age for the Saturnalia type locality, determined by uranium–lead dating, is 233.23 ± 0.61 million years old. Because this age is derived from detrital zircons, it is a maximum age and the true age might be slightly less, making the rocks approximately equivalent in age to the base of the Ischigualasto Formation, which has been found to be approximately 231.5 million years old.[6] Saturnalia is among the oldest known dinosaurs.[7]

Description

Size chart

Saturnalia was a small, bipedal animal that probably reached a length of 1.5 metres (4.9 ft)[7] and weighed between 4 and 11 kilograms (8.8 and 24.3 lb).[a] The skull of Saturnalia was only about 10 centimetres (3.9 in) long, giving it a proportionally small head as in other sauropodomorphs.[5] The neck of Saturnalia was moderately long, about 56–60% the length of the trunk, and was composed of nine or ten vertebrae.[b][9]

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.[2] However, in a 2003 paper, Langer noted that features of its skull and hand were more similar to 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.[10]

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.[11] However, all more recent cladistic analyses found it to be a very basal sauropodomorph,[12][13][14] possibly guaibasaurid, as the family was found to nest in a basal position within Sauropodomorpha.[15][16][17] The subfamily Saturnaliinae was established in 2010 by Martin Ezcurra to include Saturnalia and its close relative Chromogisaurus.[15]

Paleobiology

Life restoration

Like many other early dinosaurs, but unlike later sauropodomorphs, Saturnalia was most likely carnivorous or omnivorous, with a diet that included insects or small vertebrates.[5][18] Its small head and long neck may have allowed it to move its head rapidly enough to catch small, elusive prey.[5]

Paleoecology

Saturnalia may have been prey to the contemporary herrerasaurid Staurikosaurus.[8]

Footnotes

  1. ^ A mass of 6.5 to 11 kilograms (14 to 24 lb) was estimated based on the femur circumference.[7] Paul suggested a smaller mass of 4 kg (8 lb).[8]
  2. ^ Because the known specimens do not preserve articulated ribs and shoulder girdles, it is difficult to determine whether the tenth vertebra in the series is the last cervical or first dorsal vertebra.[9]

References

  1. ^ Langer, Max C.; Franca, Marco AG; Gabriel, Stefan (2007). "The pectoral girdle and forelimb anatomy of the stem-sauropodomorph Saturnalia tupiniquim (Upper Triassic, Brazil)". Special Papers in Palaeontology. 77: 113–137.
  2. ^ a b c d e f g Langer, Max C.; Abdala, Fernando; Richter, Martha; Benton, Michael J. (1999-10-15). "A sauropodomorph dinosaur from the Upper Triassic (Carnian) of southern Brazil" (PDF). Comptes Rendus de l'Académie des Sciences. Série 2a. Sciences de la Terre et des Planètes. 329 (7): 511–517. doi:10.1016/S1251-8050(00)80025-7. ISSN 1251-8050.
  3. ^ a b Langer, Max Cardoso (2005). "Studies on continental Late Triassic tetrapod biochronology. I. The type locality of Saturnalia tupiniquim and the faunal succession in south Brazil". Journal of South American Earth Sciences. 19 (2): 205–218. doi:10.1016/j.jsames.2005.04.003. ISSN 0895-9811.
  4. ^ "Tupiniquim". Michaelis Dicionário Brasileiro da Língua Portuguesa. Editora Melhoramentos. 2015. Retrieved 2023-12-22.
  5. ^ a b c d Bronzati, Mario; Müller, Rodrigo T.; Langer, Max C. (2019-09-06). "Skull remains of the dinosaur Saturnalia tupiniquim (Late Triassic, Brazil): With comments on the early evolution of sauropodomorph feeding behaviour". PLOS ONE. 14 (9): e0221387. Bibcode:2019PLoSO..1421387B. doi:10.1371/journal.pone.0221387. ISSN 1932-6203. PMC 6730896. PMID 31490962.
  6. ^ Langer, M.C.; Ramezani, J.; Da Rosa, Á.A.S. (2018). "U-Pb age constraints on dinosaur rise from south Brazil". Gondwana Research. X (18): 133–140. Bibcode:2018GondR..57..133L. doi:10.1016/j.gr.2018.01.005.
  7. ^ a b c Langer, Max C.; Marsola, Júlio C. A.; Müller, Rodrigo T.; Bronzati, Mario; Bittencourt, Jonathas S.; Apaldetti, Cecilia; Ezcurra, Martín D. (2022). "The Early Radiation of Sauropodomorphs in the Carnian (Late Triassic) of South America". In Otero, Alejandro; Carballido, José L; Pol, Diego (eds.). South American Sauropodomorph Dinosaurs. Cham: Springer International Publishing. pp. 1–49. ISBN 978-3-030-95958-6.
  8. ^ a b Paul, Gregory S. (2016). The Princeton Field Guide to Dinosaurs (2nd ed.). New Jersey: Princeton University Press. p. 183. ISBN 978-0691167664.
  9. ^ a b Bronzati, Mario; Rauhut, Oliver W. M.; Bittencourt, Jonathas S.; Langer, Max C. (2017-09-20). "Endocast of the Late Triassic (Carnian) dinosaur Saturnalia tupiniquim: implications for the evolution of brain tissue in Sauropodomorpha". Scientific Reports. 7 (1): 11931. Bibcode:2017NatSR...711931B. doi:10.1038/s41598-017-11737-5. ISSN 2045-2322. PMC 5607302. PMID 28931837.
  10. ^ 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.
  11. ^ Bonaparte J.F., Brea G., Schultz C.L., 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. Bibcode:2007HBio...19...73B. doi:10.1080/08912960600866862. S2CID 128421960.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  12. ^ Yates, Adam M. (2007). Barrett, Paul M.; Batten, David J. (eds.). "The first complete skull of the Triassic dinosaur Melanorosaurus Haughton (Sauropodomorpha: Anchisauria)". Evolution and Palaeobiology. 77: 9–55. ISBN 978-1-4051-6933-2.
  13. ^ Pol D., Garrido A., Cerda I.A. (2011). Farke, Andrew Allen (ed.). "A New Sauropodomorph Dinosaur from the Early Jurassic of Patagonia and the Origin and Evolution of the Sauropod-type Sacrum". PLOS ONE. 6 (1): e14572. Bibcode:2011PLoSO...614572P. doi:10.1371/journal.pone.0014572. PMC 3027623. PMID 21298087.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  14. ^ Cecilia Apaldetti, Ricardo N. Martinez, Oscar A. Alcober and Diego Pol (2011). Claessens, Leon (ed.). "A New Basal Sauropodomorph (Dinosauria: Saurischia) from Quebrada del Barro Formation (Marayes-El Carrizal Basin), Northwestern Argentina". PLOS ONE. 6 (11): e26964. Bibcode:2011PLoSO...626964A. doi:10.1371/journal.pone.0026964. PMC 3212523. PMID 22096511.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  15. ^ a b Ezcurra, M. D. (2010). "A new early dinosaur (Saurischia: Sauropodomorpha) from the Late Triassic of Argentina: a reassessment of dinosaur origin and phylogeny". Journal of Systematic Palaeontology. 8 (3): 371–425. Bibcode:2010JSPal...8..371E. doi:10.1080/14772019.2010.484650. S2CID 129244872.
  16. ^ Fernando E. Novas, Martin D. Ezcurra, Sankar Chatterjee and T. S. Kutty (2011). "New dinosaur species from the Upper Triassic Upper Maleri and Lower Dharmaram formations of central India". Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 101 (3–4): 333–349. doi:10.1017/S1755691011020093. S2CID 128620874.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  17. ^ Baron M.G., Norman D.B., Barrett P.M. (2017). "A new hypothesis of dinosaur relationships and early dinosaur evolution" (PDF). Nature. 543 (7646): 501–506. Bibcode:2017Natur.543..501B. doi:10.1038/nature21700. PMID 28332513. S2CID 205254710.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  18. ^ Ballell, Antonio; Benton, Michael J.; Rayfield, Emily J. (2022-12-16). "Dental form and function in the early feeding diversification of dinosaurs". Science Advances. 8 (50): –5201. Bibcode:2022SciA....8.5201B. doi:10.1126/sciadv.abq5201. ISSN 2375-2548. PMC 9757754. PMID 36525501.