Open Paleo

Triunfosaurus

Carvalho et al., 2017 tree-UN-fo-SOR-us

Named for the Triunfo Basin in Paraíba, Brazil, where the fossils were found, combined with Greek 'sauros' meaning 'lizard'.

143.1–125.8 million years ago Berriasian–Hauterivian, Early Cretaceous
Early Cretaceous stages

Triunfosaurus is a genus of somphospondylan sauropod dinosaur from the Early Cretaceous of Brazil. It contains a single species, T. leonardii, described by Carvalho and colleagues in 2017. It was initially described as a basal titanosaur, potentially the earliest known; however, subsequent research questioned its identification as a titanosaur and reassigned it to the Somphospondyli.

Under dispute

Triunfosaurus was described as a basal titanosaur (Carvalho and colleagues, 2017), but Poropat and colleagues (2017) reassessed it as an indeterminate somphospondylan. A redescription by Mannion and Carvalho (2026) provides a revised diagnosis and recovers it as a somphospondylan lying either just outside Titanosauria (equal weighting) or as an early-diverging titanosaur (extended implied weighting); its titanosaurian affinities cannot be excluded.

Diagnosis

  1. Small tubercle close to the distal end of the lateral surface of the anterior caudal prezygapophyses.
  2. Anterior caudal neural spines strongly expanded anteroposteriorly, the dorsal third of the spine about a third longer anteroposteriorly than the base.
  3. Anteriormost haemal arch with ridges along the lateral margins of the proximal rami, forming flange-like processes that continue onto the distal blade.

Species

Triunfosaurus leonardii Carvalho et al., 2017

Type species

Named for paleontologist Giuseppe Leonardi and Leonardi's contributions to paleontological research in Brazil.

Holotype
UFRJ-DG 498-K-R, UFRJ-DG 498-a-R, UFRJ-DG 498-b-R, UFRJ-DG 498-d-R, UFRJ-DG 498-f-R, UFRJ-DG 498-g-R, UFRJ-DG 498-h-R, UFRJ-DG 498-i-R , Universidade Federal do Rio de Janeiro, Departamento de Geologia
Material
Three articulated anterior caudal vertebrae; three isolated caudal neural spines; three proximal haemal arches; one right ischium
Horizon
Rio Piranhas Formation, Berriasian–Hauterivian, Early Cretaceous , 143.1–125.8 million years ago
Locality
Areias Farm, Paraíba, Brazil

References

  1. Carvalho, I. S.; Salgado, L.; Lindoso, R. M.; de Araújo-Júnior, H. I.; Costa Nogueira, F. C.; Soares, J. A. (2017). A new basal titanosaur (Dinosauria, Sauropoda) from the Lower Cretaceous of Brazil. Journal of South American Earth Sciences 75: 74-84. doi:10.1016/j.jsames.2017.01.010 carvalho2017a
  2. Poropat, S. F.; Nair, J. P.; Syme, C. E.; Mannion, P. D.; Upchurch, P.; Hocknull, S. A.; Cook, A. G.; Tischler, T. R.; Holland, T. (2017). Reappraisal of Austrosaurus mckillopi Longman, 1933 from the Allaru Mudstone of Queensland, Australia's first named Cretaceous sauropod dinosaur. Alcheringa: An Australasian Journal of Palaeontology 41(4): 543-580. doi:10.1080/03115518.2017.1334826

    Reappraisal of Austrosaurus that reassessed Triunfosaurus as an indeterminate somphospondylan and questioned its titanosaurian affinities.

    poropat2017a
  3. Mannion, P. D.; Carvalho, I. S. (2026). Re-evaluation of the Early Cretaceous titanosauriform sauropod dinosaur Triunfosaurus leonardii from the Triunfo Basin, Brazil: implications for the initial radiations of Somphospondyli and Titanosauria. Zoological Journal of the Linnean Society 207(1). Oxford University Press (OUP). doi:10.1093/zoolinnean/zlag073

    Redescription of the Triunfosaurus holotype with a revised diagnosis; recovers it as a somphospondylan close to or within the early titanosaur radiation.

    mannion2026a
  4. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Sauropods. Princeton University Press.

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

    jones2026b