Open Paleo

Yamanasaurus

Apesteguía et al., 2020

Named after the locality of Yamana in southern Ecuador where the fossils were found, combined with Greek sauros meaning 'lizard'; translates as 'Yamana lizard'

72.2–66.0 million years ago Maastrichtian, Late Cretaceous
Late Cretaceous stages

Yamanasaurus is an extinct genus of saltasaurine titanosaurian dinosaur from the Late Cretaceous Río Playas Formation of Ecuador. The type and only species is Yamanasaurus lojaensis, representing the first non-avian dinosaur described from Ecuador. The holotype, consisting of fragments of a humerus, radius, tibia, two sacral vertebrae and a single caudal, was discovered in 2017.

Diagnosis

  1. Anterior to mid-caudal vertebrae with a dorsoventrally compressed condyle, the posterior tip raised relative to the midline, and no longitudinal ventral ridge
  2. Spongy inner structure with absence of internal cavities (camellate bone) in anterior-mid caudal vertebrae
  3. Last sacral centrum as long as tall with small ovoid shallow blind fossa on lateral side
  4. Radius robust with flattened diaphysis and marked neck under epiphysis with heptagonal proximal articular surface

Species

Yamanasaurus lojaensis Apesteguía et al., 2020

Type species

Named for the city of Loja in southern Ecuador, where the discovery was formally presented and part of the study was carried out.

Holotype
YM-INPC-014, YM-INPC-015, YM-INPC-016, YM-INPC-017, YM-UTPL_002 , Instituto Nacional de Patrimonio Cultural
Material
Two conjoined sacral vertebrae, posterior half of a mid-caudal procoelous vertebra, proximal half of a left humerus, proximal half of a radius, and an eroded fragment possibly of a proximal tibia
Notes
The sacrum is at the Universidad Técnica Particular de Loja, the other four elements at the Instituto Nacional de Patrimonio Cultural. Apesteguía and colleagues judge them to probably belong to one animal.
Horizon
Río Playas Formation, Maastrichtian, Late Cretaceous , 72.2–66.0 million years ago
Locality
Yamana, Loja, Ecuador

References

  1. Apesteguía, S.; Soto Luzuriaga, J. E.; Gallina, P. A.; Granda, J. T.; Guamán Jaramillo, G. A. (2020). The first dinosaur remains from the Cretaceous of Ecuador. Cretaceous Research 108. Elsevier BV. doi:10.1016/j.cretres.2019.104345 apesteguía2020a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Sauropods. Princeton University Press.

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

    jones2026b