Open Paleo

Bagualia

Pol et al., 2020 bag-WAH-lee-uh

From Spanish baguala meaning 'wild horse', referencing Bagual Canyon in Chubut, Argentina, where the fossils were discovered.

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

Bagualia is an extinct genus of eusauropod dinosaur from the Early Jurassic (middle Toarcian) Cañadón Asfalto Formation in what is now the Chubut Province of Argentina. The type species, B. alba, was formally described in 2020. Bagualia represents the oldest known definitive eusauropod, and due to the completeness of its material, it represents one of the most important taxa for understanding the early evolution of the group.

Diagnosis

  1. Pointed process on the anteroventral end of the premaxilla and anterodorsal end of the dentary (autapomorphy).
  2. Anterior margin of the premaxilla without a marked step (autapomorphy).
  3. Orbital margin of the frontal with a close V-shape pointed medially, resulting in a short contribution to the orbit (autapomorphy).
  4. Supratemporal fenestra about as anteroposteriorly long as lateromedially wide (autapomorphy).
  5. Concave ventral margin of the distal portion of the cultriform process (autapomorphy).
  6. Accessory lamina below the PCDL in middle cervical vertebrae (autapomorphy).

Species

Bagualia alba Pol et al., 2020

Type species

From Spanish 'alba' meaning 'dawn', highlighting the dinosaur's early position in the sauropod lineage.

Holotype
MPEF-PV 3301 , Museo Paleontológico "Egidio Feruglio"
Material
Posterior half of skull articulated with seven cervical vertebrae.
Horizon
lower Cañadón Asfalto Formation, Toarcian, Early Jurassic , 184.2–174.7 million years ago
Locality
Bagual Canyon, Chubut, Argentina

References

  1. 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 pol2020a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Sauropods. Princeton University Press.

    Source of the body length, mass, and hip height estimates, and the appearance features.

    jones2026b