Análisis de la evolución de las extremidades en saurópodos titanosauriformes en las XL Jornadas de la SEP

Entre los trabajos presentados en las XL Jornadas de la Sociedad Española de Paleontología celebradas en Aracena (Huelva), se presentaron en una comunicación oral los resultados del estudio reciente de la evolución de las extremidades en saurópodos titanosauriformes. El trabajo titulado “Morphological convergence in the appendicular skeleton of lithostrotian titanosaurs (Sauropoda, Dinosauria) from the Ibero-Armorican domain” analiza la evolución del arqueamiento de las extremidades y trata por métodos cuantitativos y de morfometría geométrica, averiguar si existen patrones ecomorfológicos en la morfología de las extremidades de los saurópodos ligados a diferencias en la forma de aprovechar los recursos tróficos. El resumen es el siguiente:

Previous studies have identified an unusually large diversity of lithostrotian titanosaurs in the Campanian-Maastrichtian fossil record of the Ibero-Armorican domain. This diversity seems to have changed during the “Maastrichtian Dinosaur Turnover” (MDT) event, with new lineages appearing after the late early Maastrichtian. Several Ibero-Armorican titanosaurs have been erected from incomplete specimens, including limb elements. Many taxa and morphotypes display morphological resemblances in appendicular and, to a lesser extent, axial skeleton. This fragmentary record complicates taxonomic assessment and study of evolutionary processes, as it encompasses a blend of factors including morphological variability, taphonomic distortion, and evolutionary constraints that shape the morphology of the appendicular skeleton. Two lithostrotian clades, Lirainosaurinae and Opithocoelicaudiinae, have been identified on the Ibero-Armorican island. There is debate about when these lineages appeared relative to the MDT event. Recently, we suggested that some of the considered post-turnover lineages were already established in the Ibero-Armorican domain before the Campanian-Maastrichtian, however, potential ecological niche shifts can be observed in the mega-herbivorous sauropod faunas. To evaluate how the diversity of lithostrotian faunas has been influenced by adaptations to various feeding modes, this study intends to examine ecomorphological characteristics of the appendicular skeleton, which are the most common and abundant types of sauropod fossils in the Upper Cretaceous of Europe. We explore if the morphological similarities among Late Cretaceous lithostrotian underscore evolutionary convergences in the appendicular and axial skeletons, driven by adaptations to different modes of feeding niche occupation. The morphology of the appendicular skeleton in deeply branched lithostrotians does not reflect systematic differences but rather reflects the combination of a plesiomorphic greater separation of the limbs from the parasagittal plane (i.e. wide-gauge posture further development) and convergent kinematic differences that shall be explored elsewhere.

Más información:

• Referencia: Páramo, A., Mocho, P., Vidal, D., Escaso, F., Marcos-Fernández, F., Ortega, F. (2025) Morphological convergence in the appendicular skeleton of lithostrotian titanosaurs (Sauropoda, Dinosauria) from the Ibero-Armorican domain. In García-Cobeña, J., Ozkaya de Juanas, S., Romero, S. (Eds.). Libro de Resúmenes de las XL Jornadas SEP. Palaeontological Publications 8, 82.