Austroposeidon
Austroposeidon magnificus
"Magnificent southern Poseidon"
About this species
Austroposeidon magnificus is the largest dinosaur ever described from Brazil, a titanosaur roughly 25 metres long that inhabited the Late Cretaceous Bauru Basin in western São Paulo State. Its holotype MCT 1628-R was collected in 1953 by Brazilian palaeontologist Llewellyn Ivor Price on the outskirts of Presidente Prudente (SP) and sat in storage at the Museum of Earth Sciences in Rio de Janeiro for over 60 years before being formally described in 2016 by Bandeira and colleagues. The original phylogenetic analysis placed it as the sister group of Lognkosauria, while later work (Navarro et al. 2022) recovered it within Lognkosauria itself, alongside Argentinian giants such as Argentinosaurus and Patagotitan. CT scans of the cervical vertebrae revealed, for the first time in any sauropod, an internal structure alternating pneumatic camellae with dense growth rings.
Geological formation & environment
Presidente Prudente Formation, part of the Bauru Group, Bauru Basin. Campanian to early Maastrichtian age (~83 to 72 Ma). Lithology dominated by fine to medium sandstones with mudstone lenses, carbonate cementation and calcrete-bearing palaeosols. The depositional environment combines meandering fluvial systems and alluvial fans in a semi-arid climate with strong seasonality. Associated fauna includes titanosaurs, abelisaurid theropods, crocodyliforms, testudines and podocnemidid eggs.
Image gallery
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Life reconstruction of Austroposeidon magnificus, the largest dinosaur ever described from Brazil. At roughly 25 metres long, it rivals the giant titanosaurs of Patagonia.
Levi bernardo / Wikimedia Commons, CC BY-SA 3.0
Ecology and behavior
Habitat
Semi-arid fluvio-alluvial plains of the inner Bauru Basin, with meandering rivers, alluvial fans and calcrete-bearing palaeosols. Climate marked by strong rainfall seasonality and high temperatures, with vegetation dominated by shrub-like gnetophytes and small conifers.
Feeding
High-browsing herbivore, reaching conifer canopies inaccessible to other herbivores. By analogy with better-known titanosaurs, it likely ingested large volumes of barely-chewed foliage, with digestion supported by gastroliths and prolonged fermentation.
Behavior and senses
Likely gregarious like most titanosaurs, moving in groups that reshaped local vegetation. No direct evidence (tracks, nests) is associated with Austroposeidon, but the broader South American titanosaur record supports an interpretation of herd living and colonial nesting in open areas.
Physiology and growth
CT scans by Bandeira et al. (2016) revealed a unique internal vertebral structure, with pneumatic camellae alternating with dense growth rings. This pattern suggests prolonged and possibly irregular growth, consistent with sauropod gigantism strategies.
Paleogeography
Continental configuration
Ron Blakey · CC BY 3.0 · Cretáceous, ~90 Ma
During the Campaniano-Maastrichtiano (~83–72 Ma), Austroposeidon magnificus inhabited Laramidia, the western half of present-day North America, separated from the east by the Western Interior Seaway, a shallow sea dividing the continent. The continents were in very different positions: India was drifting toward Asia, Antarctica was still connected to Australia, and South America was an isolated island.
Bone Inventory
Only portions of the vertebral column were recovered (posterior cervicals, dorsals and a sacral), enough to diagnose four autapomorphies but not to reconstruct precise body proportions. Length estimates of ~25 m are inferred by comparison with more complete titanosaurs.
Found elements
Inferred elements
Scientific Literature
15 papers in chronological order — from the original description to recent research.
A new giant Titanosauria (Dinosauria: Sauropoda) from the Late Cretaceous Bauru Group, Brazil
Bandeira, K.L.N., Simbras, F.M., Machado, E.B., Campos, D.A., Oliveira, G.R. e Kellner, A.W.A. · PLOS ONE
Original description of Austroposeidon magnificus as a new giant titanosaur (~25 m), sister group to Lognkosauria. First description of a Brazilian dinosaur rivalling Patagonian giants in size. CT scans reveal a previously unrecorded pattern of growth rings alternating with pneumatic camellae in cervical vertebrae.
Internal vertebral structure of Austroposeidon (cervical CT scans)
Bandeira, K.L.N., Simbras, F.M., Machado, E.B., Campos, D.A., Oliveira, G.R. e Kellner, A.W.A. · PLOS ONE
Figure dedicated to CT-reconstructed internal structure, showing the unprecedented intercalation of pneumatic camellae with dense growth rings, interpreted as a possible marker of sustained gigantism.
Austroposeidon locality map
Bandeira, K.L.N., Simbras, F.M., Machado, E.B., Campos, D.A., Oliveira, G.R. e Kellner, A.W.A. · PLOS ONE
Geological map of the Bauru Group showing the holotype locality in the Presidente Prudente Formation, near the city of Presidente Prudente (São Paulo).
A new nanoid titanosaur (Dinosauria: Sauropoda) from the Upper Cretaceous of Brazil
Navarro, B.A., Ghilardi, A.M., Aureliano, T., Díez Díaz, V., Bandeira, K.L.N. et al. · Ameghiniana
Description of Ibirania parva, the smallest known Brazilian titanosaur. The updated phylogenetic analysis recovers Austroposeidon within Lognkosauria, revising its 2016 position as sister group.
On a titanosaurid (Dinosauria, Sauropoda) vertebral column from the Bauru Group, Late Cretaceous of Brazil
Campos, D.A., Kellner, A.W.A., Bertini, R.J. e Santucci, R.M. · Arquivos do Museu Nacional
Description of Trigonosaurus pricei based on the 'Series B' (MCT 1488-R) specimens from Peirópolis (Minas Gerais), part of the same collection in which the Austroposeidon holotype was stored for decades.
On a new titanosaur sauropod from the Bauru Group, Late Cretaceous of Brazil
Kellner, A.W.A., Campos, D.A., Trotta, M.N.F., Azevedo, S.A.K., Craik, M.M.T. e Silva, H.P. · Boletim do Museu Nacional (Geologia)
Description of Maxakalisaurus topai (MN 5013-V), a ~13 m Brazilian titanosaur from the Adamantina Formation in Minas Gerais, referred to Aeolosaurini. One of the most complete close relatives of Austroposeidon.
A new sauropod dinosaur (Titanosauria) from the Late Cretaceous of Brazil
Kellner, A.W.A. e Azevedo, S.A.K. · Proceedings of the Second Gondwanan Dinosaur Symposium, NSM Monographs
Description of Gondwanatitan faustoi, a titanosaur from São Paulo State known from a partial skeleton. The first well-documented São Paulo titanosaur, preceding Austroposeidon in the same sedimentary basin.
Uberabatitan ribeiroi, a new titanosaur from the Marília Formation (Bauru Group, Upper Cretaceous), Minas Gerais, Brazil
Salgado, L. e Carvalho, I.S. · Palaeontology
Original description of Uberabatitan ribeiroi, a titanosaur from the Marília Formation at Uberaba (Minas Gerais), Maastrichtian. Together with Austroposeidon it represents the late apex of the Brazilian titanosaurian lineage.
Description of a titanosaurid caudal series from the Bauru Group, Late Cretaceous of Brazil
Kellner, A.W.A., Campos, D.A. e Trotta, M.N.F. · Arquivos do Museu Nacional
Description of Baurutitan britoi (MCT 1490-R), a titanosaur known from sacrum and caudals from Peirópolis (Minas Gerais), Serra da Galga/Marília Formation. Anatomical comparisons support Austroposeidon's distinction as a separate taxon.
Osteology and systematics of Uberabatitan ribeiroi (Dinosauria; Sauropoda): a Late Cretaceous titanosaur from Minas Gerais, Brazil
Silva Junior, J.C.G., Marinho, T.S., Martinelli, A.G. e Langer, M.C. · Zootaxa
Complete osteological redescription of Uberabatitan ribeiroi, providing comparative context for Austroposeidon and clarifying relationships among Brazilian Maastrichtian titanosaurs.
New specimens of Baurutitan britoi and a taxonomic reassessment of the titanosaur dinosaur fauna (Sauropoda) from the Serra da Galga Formation (Late Cretaceous) of Brazil
Silva Junior, J.C.G., Martinelli, A.G., Iori, F.V., Marinho, T.S., Hechenleitner, E.M. e Langer, M.C. · PeerJ
Reassessment of the Serra da Galga Formation titanosaur fauna (Triângulo Mineiro). Expands the comparative context for interpreting Austroposeidon within the broader landscape of Campanian-Maastrichtian Brazilian titanosaurs.
New lower jaw and teeth referred to Maxakalisaurus topai (Titanosauria: Aeolosaurini) and their implications for the phylogeny of titanosaurid sauropods
França, M.A.G., Marsola, J.C.A., Riff, D., Hsiou, A.S. e Langer, M.C. · PeerJ
New dental material of Maxakalisaurus and phylogenetic analysis of aeolosaurines. Context for the lineage to which Austroposeidon approaches in the most recent analyses (Navarro et al. 2022).
Revisão estratigráfica da parte oriental da Bacia Bauru (Neocretáceo)
Fernandes, L.A. e Coimbra, A.M. · Revista Brasileira de Geociências
Stratigraphic redefinition of the eastern Bauru Basin, splitting the former Adamantina Formation into Vale do Rio do Peixe, São José do Rio Preto and Presidente Prudente. It is under this revised framework that the Austroposeidon holotype is placed stratigraphically.
Sauropod dinosaurs from the Late Cretaceous Bauru Basin: a review and taxonomic update
Nascimento, L.R.S.F., Candeiro, C.R.A., Vidal, L.S., Oliveira, A.M., Dias, L.F.F. e Brusatte, S.L. · Historical Biology
Comprehensive review of Bauru Basin sauropods integrating Austroposeidon, Trigonosaurus, Baurutitan, Uberabatitan, Gondwanatitan, Maxakalisaurus and Ibirania. Confirms Austroposeidon as the largest nominally described Brazilian dinosaur.
Novos achados de répteis Permianos e Cretáceos no Brasil
Price, L.I. · Anais da Academia Brasileira de Ciências
Short note by Llewellyn Ivor Price on new Cretaceous fossils collected in inland São Paulo, including the vertebrae later recognised as the Austroposeidon holotype. Historical record of the fieldwork that produced the specimen.
Famous museum specimens
MCT 1628-R (holótipo)
Museu de Ciências da Terra (CPRM/DNPM), Rio de Janeiro, Brasil
Holotype collected by Price on the outskirts of Presidente Prudente (São Paulo) along the Raposo Tavares road (BR-374), near the junction with the Assis Chateaubriand road (SP-425). It remained in storage for 63 years before being formally described in 2016. It is on public display at the Museum of Earth Sciences alongside a life-size forelimb reconstruction.
In cinema and popular culture
Austroposeidon has a single but memorable pop-culture appearance: it opens the episode 'Forests' (S1E5) of Apple TV+'s Prehistoric Planet series in 2022. The scene depicts a herd of the titanosaur feeding and pushing over trees in a Late Cretaceous South American forest, narrated by David Attenborough. Beyond this appearance, the animal remains absent from films, documentaries or games — a common fate for Brazilian dinosaurs, rarely represented in international mass media.
Classification
Discovery
Fun fact
The Austroposeidon holotype sat in storage for 63 years at the Museum of Earth Sciences in Rio de Janeiro before being formally described. Collected in 1953 by Llewellyn Ivor Price, the material was only recognised as a new species in 2016, when Bandeira and colleagues first noticed a unique pattern of pneumatic camellae alternating with dense growth rings, visible only through CT scanning. It remains the largest named dinosaur from Brazil.