Trinisaura

Coria et al., 2013 TRIH-nee-SOR-uh

Named to commemorate Argentine geologist Trinidad 'Trini' Diaz, combined with Greek sauros ('lizard')

83.6–72.2 million years ago Campanian, Late Cretaceous

Late Cretaceous stages

Trinisaura is a genus of ornithopod dinosaur that lived during the late Campanian stage of the Upper Cretaceous, around 73 to 72 million years ago in what is now James Ross Island off the coast of northern Antarctica near Patagonia. It is known from a single, incomplete postcranial skeleton that includes several vertebrae, a partial pelvis, and nearly complete right hindlimb. The fossils were collected in 2008 by paleontologists Juan Moly and Rodolfo Coria from the sandstone of the Snow Hill Island Formation. It remained undescribed in the collections of the Museo de La Plata until its description by Coria and colleagues in 2013, being the basis of the novel genus and species Trinisaura santamartaensis. The genus name is to commemorate the efforts of Argentine geologist Trinidad "Trini" Diaz and the Latin root -sauros, meaning "lizard". The species name is after Santa Marta Cove, where the fossils were collected.

Diagnosis

Scapula with spike-like acromial process with strong sharp lateral crest, longer than in other ornithopods
Rudimentary deltopectoral crest as shallow thickening on anterolateral margin of humerus shaft
Humeral shaft strongly bowed laterally
Ischium gently curved along entire length

Species

Trinisaura santamartaensis Coria et al., 2013

Type species

Named for Santa Marta Cove on James Ross Island, Antarctica, where the holotype was collected.

Holotype: MLP08-III-1-1 , Museo de La Plata
Material: Disarticulated partial skeleton including dorsal vertebra, sacral centra, caudal vertebrae, dorsal ribs, haemal arch, scapulocoracoid, humerus, metacarpals, ilia, pubis, ischium, femur, tibia, metatarsal, pedal phalanges
Horizon: Gamma Member, Snow Hill Island Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
Locality: Santa Marta Cove, Antarctica

References

Coria, R. A.; Moly, J. J.; Reguero, M.; Santillana, S.; Marenssi, S. (2013). A new ornithopod (Dinosauria; Ornithischia) from Antarctica. Cretaceous Research 41: 186-193. Elsevier BV. doi:10.1016/j.cretres.2012.12.004 coria2013b
Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.
Source of the mass and hip height estimates.
jones2026a