De la colaboración del sector oológico del GBE con colegas de Rumanía nos llega el póster “Maastrichtian dinosaur eggshells from Transylvanian and Hațeg sedimentary basins (Romania) unveil the northernmost occurrence of Fusioolithidae”. En este trabajo se reportan restos atribuibles a Fusioolithus baghensis en dos yacimientos rumanos de la célebre cuenca de Hațeg y de la cuenca de Transilvania del final del Cretácico. Estos hallazgos suponen la aparición más septentrional de la ooespecie, y presentan diferencias entre ellos y semejanzas con los restos encontrados en otros yacimientos europeos, como Poyos (Guadalajara, Spain), que refuerzan las evidencias sobre su gran variabilidad intraooespecífica. Abajo dejamos el resumen:
The presence of isolated Maastrichtian eggshells at the Oarda de Jos and Nălaț-Vad sites, in the sedimentary basins of Transylania and Hațeg, is here reported. In both basins, the sedimentary infill sequences refer to fluvial environments, with volcanic inputs. These rocks are famous due to their vertebrate fossils: fish, amphibians, lacertilians, dinosaurs, pterosaurs, birds, and mammals. Eggshells from both localities have dinosaur-spherulitic basic type, tubospherulitic morphotype with partially fused spheroliths, tubocanaliculate pore system and compactituberculated ornamentation with some nodes connected by ridges. This trait combination is compatible with the widespread oospecies Fusioolithus baghensis, and thus these Romanian specimens represent the northernmost known occurrence of Fusioolithidae. Though differences in histostructural features between the specimens from those sites, particularly related to eggshell thickness and node shape, have been observed, all of them more closely resemble other European specimens rather than those from Gondwana. Eggshells from Nălaț-Vad are slightly thicker than the typical Fusioolithus baghensis eggshells, being similar to those from Coll de Nargó and Orcau-1 sites (Lleida, Spain) but with predominantly dome- or wave-shaped nodes. The Oarda de Jos specimens are more akin to the Fusioolithus baghensis specimens from Poyos fossil site (Guadalajara, Spain), being remarkably thin with bell- or wave-shaped nodes. Interestingly, eggshells from both Romanian sites have spheroliths with a higher height/width ratio than most worldwide sites, being only comparable to those from Poyos. Fusioolithus baghensis eggs with in ovo titanosaurian sauropod embryos have been reported from Gondwana. The titanosaur diversity in the European record is still poorly understood, but they were subject to vicariant processes between islands and insularity at the end of the Cretaceous. The unclear phylogenetic connections between titanosaurs in Romania and Spain underscore the significance of these findings in shedding light on the evolutionary history and distribution patterns of these dinosaurs during the European Upper Cretaceous.
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