Bagualia (meaning "wild horse"), is an extinct genus of eusauropod dinosaur, from the Early Jurassic (Middle Toarcian) Epoch in what is now the Chubut Province of Argentina.

The Bagualia fossil material was discovered in Bagual Canyon, approximately 4.3 kilometres (2.7 mi) from Cerro Cóndor in Chubut, Argentina within the Early Jurassic deposits of the Cañadón Asfalto Formation.

The size of Bagualia was likely brought on by a newly formed ecosystem and climate shifts, which were all caused by volcanic activity in the Southern Hemisphere during the Early Jurassic.

The digestive system of Bagualia was also a likely reason why it grew to such a large size, and another function of its long neck has been proposed: it may have dissipated heat in a similar fashion to how elephants use their ears.

The rhomboid-shaped left prefrontal features prominent articular facets for the lacrimal, nasal, and frontal bones, characterized by its elongated shape and triangular cross-section.

It features limited cranial pneumaticity and lacks certain recesses, with an elliptical foramen magnum dorsoventrally oriented, contrasting with the circular shape seen in many non-sauropod sauropodomorphs.

Notably, these dentaries exhibit a U-shaped configuration characteristic of eusauropods, featuring unique structural traits, including well-developed alveoli and a prominent coronoid process on the surangular.

The teeth are spoon-shaped with heavily wrinkled enamel, displaying asymmetrical mesial and distal margins, characteristic of many sauropodomorphs, with notable features like a medial convex area and a procumbent arrangement typical of eusauropods.

[4] Cervical ribs feature a tetraradiate shape at their proximal ends, characterized by a prominent tuberculum, capitulum, and anterior process, along with a long, slender shaft directed posteriorly, consistent with most sauropods.

In the posterior caudal vertebrae, the centra are significantly longer than tall, lacking transverse processes and lateral fossae, with decreasing neural spine angles observed towards the tail's end.

Due to its provenance from the Cañadon Asfalto Formation, which is dated to the Toarcian, its describers interpret this as evidence of a eusauropod dominance after an Early Jurassic global warming event, replacing more basal sauropodomorphs.

[6] Palustrine littoral environment levels are seen at Cerro Cóndor and Estancia Fossati, characterized by the presence of lacustrine limestones interbedded with shales, tuffs and sandstones.

[8][9] Bagualia has important paleoecological implications due to its robust skull and broad teeth, which indicate a shift towards bulk browsing on tough vegetation, such as conifers from families like Araucariaceae, Cheirolepidiaceae, and Cupressaceae after the Toarcian Oceanic Anoxic Event, what may have been a key for their success after local environmental change.

[10] The features of Bagualia highlight a key evolutionary step between early sauropodomorphs and derived eusauropods, suggesting significant ecological interactions as environments changed.