The Tetrapod Fossil Record from the Uppermost Maastrichtian of the Ibero-Armorican Island: An Integrative Review Based on the Outcrops of the Western Tremp Syncline (Aragón, Huesca Province, NE Spain)

The South-Pyrenean Basin (northeastern Spain) has yielded a rich and diverse record of Upper Cretaceous (uppermost Campanian−uppermost Maastrichtian) vertebrate fossils, including the remains some last European dinosaurs prior to Cretaceous-Paleogene (K-Pg) extinction event. In this work, we update characterize fossil Arén Sandstone Tremp formations in Western Syncline, which is located Aragonese area Southern Pyrenees. transitional continental successions these sedimentary units are dated late Maastrichtian, exploration their outcrops led discovery numerous (bones, eggshells, tracks) dinosaurs, hadrosauroids, sauropods, theropods, along with other tetrapods such as crocodylomorphs, testudines, pterosaurs, squamates, amphibians. particular, contains youngest lambeosaurine hadrosaurids (Arenysaurus Blasisaurus) Mesozoic crocodylomorphs (Arenysuchus Agaresuchus subjuniperus) Europe, complementing lower Maastrichtian sites Eastern Syncline. addition, faunal comparison Hațeg island reveals great change dinosaur assemblages resulting from arrival on Ibero-Armorican island, whereas those Haţeg remained stable. light its paleontological richness, stratigraphic continuity, calibration within few hundred thousand years Cretaceous, Syncline one best places Europe study latest Archipelago before end-Cretaceous mass extinction.