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Astigmasaura genuflexa Bellardini, Filippi, Carballido, Garrido & Baiano, 2025 Artwork by Mattia Yuri Messina facebook.com: MYM PaleoArt |
Abstract
Rebbachisaurids are medium to large-sized, non-selective and ground-level browser diplodocoid sauropods, and they are characterised by highly specialised skulls, widely pneumatized axial elements and gracile appendicular skeletons. Known from the Early Cretaceous to the early Late Cretaceous, the rebbachisaurid fossil record is particularly diversified in Gondwana, with several specimens found in North Africa and South America. Notably, Patagonia has yielded over more than half of all known Rebbachisauridae, including the most basal forms and the youngest rebbachisaurid remains to date. Herein, we describe a new species of Rebbachisauridae from the Huincul Formation (upper Cenomanian) of the Neuquén Basin (Patagonia, Argentina): Astigmasaura genuflexa gen. et sp. nov. New laboratory work provided the complete osteology of the specimen MAU-Pv-EO-629, complementing the previously published hind limb anatomy. Thus, the type material of Astigmasaura comprises the posterior portion of an articulated, postcranial skeleton of a single, morphologically adult individual. Astigmasaura shares different conditions with other Rebbachisauridae, including anterior caudal vertebrae with tall neural spines and tetraradiate neural laminae, asymmetric middle haemal arches, mediolaterally compressed proximal tibiae, and femur with medially inclined distal condyles. Furthermore, Astigmasaura shows a unique combination of diagnostic features that distinguish it from all other sauropods. This new record not only provides new morphological information about the caudal and pelvic girdle anatomy of Rebbachisauridae, which is poorly known to date, and suggests a greater taxonomic diversification within the family during the last stages of its evolutionary history than known before.
Systematic palaeontology
Order Saurischia Seeley, 1887
Suborder Sauropodomorpha von Huene, 1932
Infraorder Sauropoda Marsh, 1878
Superfamily Diplodocoidea Marsh, 1884 (sensu Upchurch, 1995)
Family Rebbachisauridae Bonaparte, 1997
Astigmasaura genuflexa gen. et sp. nov.
Etymology. The generic name is derived from El Orejano, a locality in North Patagonia from which the new taxon was found. Orejano is a Spanish word denoting an animal without identification signs or owner, ...
Flavio Bellardini, Leonardo S. Filippi, José L. Carballido, Alberto C. Garrido and Mattia A. Baiano. 2025. Side by side with Titans: A New rebbachisaurid Dinosaur from the Huincul Formation (upper Cenomanian) of Patagonia, Argentina. Cretaceous Research. 176, 106188. DOI: doi.org/10.1016/j.cretres.2025.106188
https://www.conicet.gov.ar/descubren-en-neuquen-una-nueva-especie-de-dinosaurio-sauropodo-que-vivio-hace-95-millones-de-anos/