Open Paleo

Patagosaurus

Bonaparte, 1979 PAT-a-go-SAWR-us

Named for Patagonia, the region of Argentina where it was found, combined with Greek 'sauros' meaning 'lizard'; translates as 'Patagonia lizard'.

184.2–174.7 million years ago Toarcian, Early Jurassic
Early Jurassic stages

Patagosaurus is an extinct genus of eusauropod dinosaur from the middle Toarcian of Patagonia, Argentina. It was first found in deposits of the Cañadón Asfalto Formation, which date to around 178 million years ago. Although originally twelve specimens were assigned to the taxon, at least one of them may belong to a different genus. Patagosaurus probably lived alongside genera such as Piatnitzkysaurus, Condorraptor, and Volkheimeria.

Diagnosis

  1. Cetiosaurid of large size with tall dorsal vertebrae and posterior dorsals with elevated neural arches.
  2. Posterior dorsal neural spines formed from 4 divergent laminae with massive dorsal region and dorsoventrally-oriented neural spine cavities, more expanded than in Barapasaurus.
  3. Sacrum with 5 vertebrae, elevated neural spines, and large dilation of the neural canal forming a neural cavity.
  4. Pelvis with pubis showing distal and proximolateral expansions more developed than in Barapasaurus, and less expanded pubic symphysis than in Amygdalodon.
  5. Ischium slightly transversely compressed with ventromedial ridge of sublaminar type and clear distal expansion.
  6. Tibia-femur length ratio of 1:1.5 in juveniles, reaching 1:1.7 in adults.

Species

Patagosaurus fariasi Bonaparte, 1979

Type species

Named for Ricardo Farias, on whose land in the Cañadón Asfalto region of Patagonia the initial discovery was made.

Holotype
PVL 4170 , Colección de Paleontologia de Vertebrados de la Fundación Instituto Miguel Lillo
Material
Almost complete postcranial skeleton including cervical, dorsal, sacral and caudal vertebrae, ribs, haemal arches, ilium, ischia, pubis, scapula, coracoid, humerus, and femur.
Horizon
lower Cañadón Asfalto Formation, Toarcian, Early Jurassic , 184.2–174.7 million years ago
Locality
Cerro Cóndor North, Chubut, Argentina Pol and colleagues (2022) report that "The base of the Cañadón Asfalto Formation was dated at 179.17 ± 0.12 Ma, and the uppermost levels of this unit were dated at 178.07 ± 0.21 Ma", and that "The locality where Volkheimeria and Patagosaurus were found is stratigraphically bracketed between the horizons of these two dates", placing them "into the middle Toarcian (ca 179–178 Ma)". That replaces the early Middle Jurassic age Cúneo and colleagues (2013) gave these sauropods.

References

  1. Bonaparte, J. F. (1979). Dinosaurs: A Jurassic Assemblage from Patagonia. Science 205(4413): 1377-1379. American Association for the Advancement of Science (AAAS). doi:10.1126/science.205.4413.1377 bonaparte1979a
  2. Bonaparte, J. F. (1986). Les Dinosaures (Carnosaures, Allosaurides, Sauropodes, Cetiosaurides) du Jurassique moyen de Cerro Cóndor (Chubut, Argentine) [The Dinosaurs (Carnosaurs, Allosaurids, Sauropods, Cetiosaurids) of the Middle Jurassic of Cerro Cóndor (Chubut, Argentina)]. Annales de paléontologie 72(4): 325-386.

    In French. Full descriptive monograph complementing the brief Bonaparte (1979) announcement; covers Patagosaurus fariasi material in detail.

    bonaparte1986b
  3. Cúneo, R.; Ramezani, J.; Scasso, R.; Pol, D.; Escapa, I.; Zavattieri, A. M.; Bowring, S. A. (2013). High-precision U-Pb geochronology and a new chronostratigraphy for the Cañadón Asfalto Basin, Chubut, central Patagonia: implications for terrestrial faunal and floral evolution in Jurassic. Gondwana Research 24(3-4): 1267-1275. Elsevier BV. doi:10.1016/j.gr.2013.01.010

    Dates the interval overlying the uppermost basalt flow at Cerro Cóndor, which holds this taxon, as Aalenian to probably Bajocian, with a latest Toarcian age not precluded near the basalt.

    cúneo2013a
  4. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Sauropods. Princeton University Press.

    Source of the hip height estimate.

    jones2026b
  5. Pol, D.; Gomez, K.; Holwerda, F. M.; Rauhut, O. W. M.; Carballido, J. L. (2022). Sauropods from the Early Jurassic of South America and the Radiation of Eusauropoda. South American Sauropodomorph Dinosaurs: Record, Diversity and Evolution 131-163. Springer International Publishing. doi:10.1007/978-3-030-95959-3_4

    Brackets the type locality between U-Pb dates in the middle Toarcian.

    pol2022a
  6. Pol, D.; Ramezani, J.; Gomez, K.; Carballido, J. L.; Carabajal, A. P.; Rauhut, O. W. M.; Escapa, I. H.; Cúneo, N. R. (2020). Extinction of herbivorous dinosaurs linked to Early Jurassic global warming event. Proceedings of the Royal Society B: Biological Sciences 287(1939): 20202310. The Royal Society. doi:10.1098/rspb.2020.2310

    Source of the U-Pb dates for the base and top of the formation.

    pol2020a