R. Gaete

ABSTRACT Pterosaur bones are for the first time reported from the Tremp Syncline (Spain) and the southern Pyrenees. They come from the Torrebilles‐2 site (Isona, Lleida Province) in the upper Maastrichtian part of the Tremp Formation, which falls within the C29r magnetochron. Fragmentary long bones are referred to the Pterosauria based on their cortical thinness, micro‐architecture, and histological features. They belong to very large to possibly giant individuals. The most complete specimen is possibly a partial right femur. The review of the Maastrichtian pterosaur record shows that only a few specimens can be referred to the C29r (which contains the K/Pg boundary). The identification of fragmentary remains could improve our knowledge about the abundance and distribution of these flying sauropsids just before the end‐Cretaceous mass extinction.

ABSTRACT European Maastrichtian dinosaur faunas are important to understand the last stages of dinosaur evolution before their extinction out of North America, where they have been studied more extensively. Localities such as the ones in the South-Pyrenean area provide long and well-dated sections with an outstanding record of dinosaur remains and other vertebrates, invertebrates, and plants. This record also contains the K/T boundary. Recent progress in the physical and time-correlation of different sections in the area are leading to a clear succession of events. The study of the site-forming processes and environments where dinosaur fossils are found, also contribute to detect the influence on the dinosaur succession. The over or under-representation of taxa in the succession (due to paleoenvironment and site forming processes) is also controlled after sedimentological studies. In the Vallcebre syncline (South-Eastern Pyrenees) there is a succession of Maastrichtian strata up to 400 meters thick that belongs to the Tremp Formation. The age of the Vallcebre section is well constrained after the occurrence of a clear magnetostratigraphic succession that can be compared to the standard polarity scale after biochronological constraints. Dinosaur taxa include titanosaur sauropods, dromeaeosaurid theropods and hadrosaur ornithopods. The succession in the eastern part of the Tremp basin (South-Central Pyrenees) is 450 meters thick and belongs to the Aren and Tremp Formations. Dinosaur record consists of titanosaur sauropods, nodosaurid ankylosaurs, dromeaeosaurid theropods, basal hadrosauroid ornithopods, hadrosaurine ornithopods and lambeosaurine ornithopods. On the whole, titanosaurid remains, although present throughout the series, mainly occur in the basalmost part in deposits of the Aren Fm and those of the grey unit of the Tremp Fm. Nodosaurid ankylosaurs are present only in the basalmost deposits of the series. Theropods are found all through the series. Basal hadrosauroid and hadrosaurine ornithopods occur throughout the series, although less frequently in the lower part. However, they are abundant in the mid and upper part. Regarding lambeosaurine ornithopod remains, they are present in a particular moment close to the K-T boundary. The whole record makes the South-Pyrenean area a remarkable succession to contribute to the understanding of the last European dinosaurs.

ABSTRACT The eastern Tremp Syncline (northeastern Spain) is the richest European locality for latest Cretaceous hadrosauroids. We summarize the record of hadrosauroid skeletal remains from 33 localities and tracks from 15 sites in the Tremp Formation. Two of the bone-bearing localities occur in the Early/Late Maastrichtian “gray unit,” whereas all other sites occur in the Late Maastrichtian “lower red unit.” The skeletal sample represents more than 1,000 elements, mostly axial and appendicular, although several mandibular and skull bones have been recovered. The eastern Tremp Syncline includes the hitherto only known hadrosauroid bonebed from Europe, as well as the “tsintaosaur” lambeosaurine Pararhabdodon isonensis. Hadrosauroids are less abundant than sauropods in the gray unit, whereas they are much more abundant in the overlying lower red unit where sauropod bones are rare. This turnover is best explained as a time/event-related faunal change at the beginning of the Late Maastrichtian. The apparent absence of hadrosauroid eggshells and hatchlings suggests that the nesting grounds of these animals occurred far from the depositional areas of the Tremp Syncline, thus remaining unrecorded unlike the eggremains of coeval sauropods. The skeletal sample is mostly composed of individuals much smaller than those regarded as adults for the hadrosaurid taxa of the latest Cretaceous of western North America and Asia, although a few larger individuals in the adult size range exist. This may be explained by the prevalence of juvenile individuals compared to adults, the presence of both small and large-sized species in the sample, or by the occasional presence of unusually large individuals within populations of relatively moderate body size, and possibly dwarfs.

Southwestern Europe is a key setting to evaluate the diversity of non-avian dinosaurs before the end of the Cretaceous (below the K–Pg boundary). The ancient Ibero-Armorican Island, encompassing the current regions of North-East Iberia and South France, provides a substantial record of sauropod fossils. The study of multiple sauropod femora from localities where upper Campanian to uppermost Maastrichtian successions are both exposed, together with the integration of the information gathered from previously known localities ...

ABSTRACT The hadrosauroid dinosaur Pararhabdodon isonensis is known from partial cranial and postcranial material from the Maastrichtian of the south Pyrenean foredeep basin (northern Catalunya, Spain). We revise and emend the taxonomic history, ...

ABSTRACT Nuevos hallazgos de dinosaurios y otros tetrápodos continentales en los Pirineos sur-centrales y orientales: resultados preliminares New dinosaur and other continental tetrapods fi ndings from the South-central and Eastern Pyrenees: preliminary results Recibido el 6 de febrero de 2005, aceptado el 15 de febrero de 2006. Resumen Durante los últimos cinco años, se ha iniciado un estudio multidisciplinar de la geología y paleontología de los materiales continentales del fi nal del Cretácico que afl oran en diferentes áreas de los Pirineos meridionales y orien-tales de Catalunya. Estas áreas comprenden las comarcas leridanas del Pallars Jussà (Cuenca de Tremp), Alt Urgell (Coll de Nargó) y la Noguera, así como la comarca barcelonesa del Berguedà (Sinclinal de Vallcebre). Los sedimen-tos de transición y continentales de las Formaciones Areniscas de Arén y Tremp (Campaniense-Maastrichtiense) han proporcionado durante los últimos cincuenta años un importante registro fósil de vertebrados. Yacimientos de huevos, huellas y huesos se describieron principalmente durante los años ochenta e inicios de los noventa. Aquellas localidades "clásicas" representaron las primeras evidencias que contribuyeron a un conocimiento preliminar de las faunas de vertebrados del Cretácico tardío. En la primera fase de trabajo de este nuevo proyecto de estudio se han identifi cado importantes localidades con un alto potencial paleontológico en estas cuatro áreas. Los nuevos hallaz-gos se han producido en los recientes yacimientos descubiertos, pero también han vuelto a ser excavadas algunas localidades "clásicas". Los nuevos hallazgos incluyen 13 localidades con huesos, 15 yacimientos con huevos y 12 yacimientos con huellas. Los huesos, huevos y huellas fósiles recuperados y descritos pertenecen principalmente a hadrosáuridos, titanosaurios, terópodos,, Escuer, J. (2006): Nuevos hallazgos de dinosaurios y otros tetrápodos continentales en Los Pirineos sur-centrales y orientales: resultados preliminares. En (Colectivo Arqueológico-Paleontológico Salense, Ed.): Actas de las III Jornadas sobre Dinosaurios y su Entorno. 365-378. Salas de los Infantes, Burgos, España.

Resumen La fauna de hadrosaurios finicretácicos del continente europeo es diversa. Al igual que en Norteamérica y Asia el registro europeo incluye representantes de hadrosaurinos y lambeosaurinos, y además se han encontrado posibles hadrosauroideos basales y hadrosáuridos basales no euhadrosáuridos. Esto último distingue a la fauna europea del resto de Laurasia (Weishampel et al., 1993; Horner et al., 2004; Pereda-Suberbiola et al., 2009a, 2009b; Dalla Vecchia, 2009; Cruzado-Caballero et al., 2010a, ...