Open Paleo

Bajadasaurus

Gallina et al., 2019 bah-HAH-dah-SOR-us

Named after La Bajada, the locality in Patagonia, Argentina where it was found, combined with Greek sauros meaning 'lizard'. Full meaning: 'Bajada lizard'.

137.1–132.6 million years ago Valanginian, Early Cretaceous
Early Cretaceous stages

Bajadasaurus is a genus of sauropod dinosaur from the Early Cretaceous epoch (late Berriasian to Valanginian stages, between 145 and 132.9 million years ago) of northern Patagonia, Argentina. It was first described in 2019 based on a single specimen found in 2010 that includes a largely complete skull and parts of the neck. The only species is Bajadasaurus pronuspinax. The genus is classified as a member of the Dicraeosauridae, a group of relatively small and short-necked sauropods.

Diagnosis

  1. Post-temporal fenestra extended medially with a long parietal contribution (autapomorphy)
  2. Basipterygoid processes extremely slender and long, more than six times longer than lateromedially wide (autapomorphy)
  3. Elongate angular, longer than the anteroposterior surangular length
  4. Neural spine of the axis oriented vertically (autapomorphy)
  5. Paired, anteriorly curved, and extremely elongate bifid neural spines of anterior-mid cervical vertebrae (autapomorphy)

Species

Bajadasaurus pronuspinax Gallina et al., 2019

Type species

From Latin 'pronus', meaning 'bent over forward', and the Greek 'spinax', meaning 'spine', referring to the long and forward-curved neural spines of the neck.

Holotype
MMCH-Pv 75 , Museo Municipal ‘Ernesto Bachman’, Villa El Chocón
Material
Nearly complete skull, both proatlases, atlantal neurapophyses, axis, and the ?fifth cervical vertebra
Horizon
Bajada Colorada Formation, Valanginian, Early Cretaceous , 137.1–132.6 million years ago
Locality
Neuquén, Argentina

References

  1. Gallina, P. A.; Apesteguía, S.; Canale, J. I.; Haluza, A. (2019). A new long-spined dinosaur from Patagonia sheds light on sauropod defense system. Scientific Reports 9(1). Springer Science and Business Media LLC. doi:10.1038/s41598-018-37943-3 gallina2019a
  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