Austroposeidon
From Latin austro- meaning 'southern' + Poseidon (Ποσειδῶν), the Greek god of the sea, used in the name as a reference to enormous size (as in Sauroposeidon); overall meaning 'Southern Poseidon'.
Austroposeidon is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous Presidente Prudente Formation of Brazil. It contains one species, Austroposeidon magnificus (meaning "Magnificent Southern Poseidon").
Under dispute
Placed conservatively within Colossosauria. The describing analysis (Bandeira and colleagues, 2016) recovered Austroposeidon as the sister group of Lognkosauria rather than within it, whereas a later analysis (Navarro and colleagues, 2022) recovered it inside Lognkosauria; most other studies leave it unresolved owing to its fragmentary remains. Colossosauria is the least-inclusive node these placements share.
Diagnosis
- Columnar-like centropostzygapophyseal laminae (cpol) in the last cervical vertebrae (Cv 13), with proximal and distal expansions reaching nearly the height of the centrum
- Last cervical vertebra bearing a bifurcated posterior centrodiapophyseal lamina (pcdl), each segment inclined dorsally and diverging from the posteriormost portion
- First dorsal vertebra with anterior and posterior centrodiapophyseal laminae (acdl/pcdl) curved ventrolaterally and with the diapophysis reaching the dorsal margin of the centrum
- Anteriormost portion of the spinoprezygapophyseal laminae (sprl) forked in the posterior dorsal vertebra
Species
Austroposeidon magnificus Bandeira et al., 2016
Type species
From Latin 'magnificus' meaning 'great, elevated, noble', referring to the large size of the specimen.
- Holotype
- MCT 1628-R , Museu da Divisão de Geologia e Mineralogia
- Material
- Two incomplete cervical vertebrae, one cervical rib, one dorsal vertebra, seven fragments of dorsal vertebrae, and a fragment of a sacral vertebra
- Horizon
- Presidente Prudente Formation, Campanian–Maastrichtian, Late Cretaceous , 83.6–66.0 million years ago
- Locality
- Raposo Tavares road, near the Assis Chateaubriand road, São Paulo, Brazil
References
- Bandeira, K. L. N.; Medeiros Simbras, F.; Batista Machado, E.; de Almeida Campos, D.; Oliveira, G. R.; Kellner, A. W. A. (2016). A New Giant Titanosauria (Dinosauria: Sauropoda) from the Late Cretaceous Bauru Group, Brazil. PLOS ONE 11(10): e0163373. Public Library of Science (PLoS). doi:10.1371/journal.pone.0163373 bandeira2016a
-
Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Sauropods. Princeton University Press.
Source of the mass and hip height estimates.
jones2026b