El encuentro anual de la Society of Vertebrate Paleontology se realizó el pasado año en la ciudad de Toronto en Canadá. En esta última edición, hemos sido seleccionados para realizar una comunicación oral con un trabajo presentado por Pedro Mocho del Insituto Dom Luiz (Faculdade de Ciências, Universidade de Lisboa) y del Grupo de Biología Evolutiva de la UNED. En este comunicación se presentaron los hallazgos más recientes acerca de los saurópodos titanosaurios del yacimiento de Lo Hueco y la importancia de este importante registro para comprender la problemática sistemática de este grupo del Campaniense-Maastrichtiense Europeo. En la charla se expusieron algunos de los resultados preliminares de los análisis filogenéticos que están siendo realizados. El resumen es el siguiente:
The Campanian-Maastrichtian strata of the Ibero-Armorican domain (Southwestern Europe) are rich in titanosaur remains with six described taxa. Most of these taxa are mainly represented by holotypes restricted to a single bone or a small set of associated bones plus referred material from the same multi-taxic bone beds in which the degree of skeletal articulation or association is low and where more than one titanosaur taxon may be represented. As a result, the systematics of the Late Cretaceous Ibero-Armorican titanosaurs is complex due the absence of partially complete titanosaurian specimens with unquestionable association. This scenario dramatically changed with the discovery of the Lo Hueco fossil-site in Cuenca (Spain), a Campanian-Maastrichtian multi-taxic bonebed from the Villalba de la Sierra Formation, which has yielded more than 10,000 fossils of which nearly half correspond to titanosaurian remains, including more than 10 partial skeletons, mostly articulated or with low dispersion. The study of these specimens is key for the understanding of the complex systematics of Late Cretaceous European titanosaurs. Preliminary comparisons suggested the presence of at least two titanosaurian morphotypes based on two types of cranial morphologies, teeth, and appendicular bones. However, higher disparity has been observed in the axial skeleton, especially in the dorsal and caudal vertebrae, and the presence of up to four different taxa in Lo Hueco is not ruled out. In 2016, Lohuecotitan pandafilandi was the first established taxon, considered to be a lithostrotian titanosaur. Here, we briefly present seven new and partially complete titanosaurian individuals (HUE-EC-02, HUE-EC-03, HUE-EC-04, HUE-EC-05, HUE-EC-06, HUEEC-11 and HUE-EC-13), including the most complete lithostrotian of Europe (HUE-EC-02), with an almost complete axial series from the anterior cervical to the middleposterior caudal vertebrae. These new specimens provide relevant information for formulation and scoring of morphological characters. Our preliminary phylogenetic analyses have recovered Lohuecotitan, HUE-EC-02 and Paludititan as possible members of Lirainosaurinae together with Lirainosaurus, from the upper Campanian-Maastrichtian site of Laño (Treviño County), and Ampelosaurus and Atsinganosaurus, from the Upper Cretaceous of southern France. Our cladistic analyses supports the presence of at least one clade of exclusive forms in the European realm.
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