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Thin fossil eggshell from Upper Cretaceous deposits of Europe, characterized by nodular ornamentation similar to modern gekkotan eggshell, has mostly been interpreted as gekkotan (=‘geckoid’) in origin. However, in some cases, as for the oogenus Pseudogeckoolithus, a theropod affinity has also been suggested. The true affinity of these fossil ‘geckoid’ eggshells has remained controversial due to the absence of analytical methods for identifying genuine gecko eggshell in the fossil record. In this study, we apply electron backscatter diffraction (EBSD) analysis to latest Cretaceous European ‘geckoid’ (including Pseudogeckoolithus) eggshell, in comparison with modern gekkotan and theropod (avian) eggshell. We found that Pseudogeckoolithus has a definite theropod eggshell-like crystallographic configuration, in clear contrast to that seen in modern ‘gecko eggshells’. Furthermore, the crystallography of the nodular ornamentation in Pseudogeckoolithus is similar to that seen in megapode eggshell, but different from that of gecko eggshell, despite superficial morphological similarity. The remarkable morphological similarities between Pseudogeckoolithus and modern gecko eggshells are thus convergent, and the ‘gekkotan affinity’ hypothesis can be dismissed for Pseudogeckoolithus. This study provides a template for differentiating true gekkotan from dinosaurian eggshells in the fossil record. The potential functional significance of eggshell ornamentation, lost in most modern birds, requires further study, and experimental zoological approach may shed light on this issue. Finally, the present results suggest caution about the dangers of using potentially homoplastic eggshell characters in eggshell parataxonomy.

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

The Spheroolithidae oospecies Guegoolithus turolensis, putatively attributed to non-hadrosauroid styracosterns was first described in the Barremian of the Iberian Basin, and later reported in the Valanginian–Hauterivian of the Cameros Basin, with both occurrences separated by a few hundred kilometres but by over 10 million years. Here we apply electron backscatter diffraction to search for crystallographic and ultrastructural differences between both occurrences of this ootaxon. Not only did not we found significant differences between eggshells from the two basins, probably laid by different non-hadrosauroid styracostern species but also, we found significant similitudes with the Late Cretaceous Maiasaura eggshells from North America. All Spheroolithidae eggshells are characterized by a profusion of low angle misorientation boundaries within larger orientation domains, that fan out from the eisospherite. A very quick reorientation of the c-axis of the crystals is observed, and explained partially via competitive growth. This conservative eggshell architecture suggests that the physical properties of the eggshell of styracosterns remain unchanged for at least 80 million years, implying similar nesting and breeding behaviours.

Fil: Moreno Azanza, Miguel. Universidade Nova de Lisboa; Portugal. Fil: Moreno Azanza, Miguel. Universidad de Zaragoza; España Fil: Gasca Pérez, José M. Universidad de Zaragoza; España Fil: Gasca Pérez, José M. Provincia de Neuquén. Ministerio de Energía, Ambiente y Servicios Públicos. Dirección Provincial de Minería. Museo Provincial de Ciencias Naturales Prof. "Dr. Juan A. Olsacher"; Argentina Fil: Díaz Martínez, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; Argentina Fil: Díaz Martínez, Ignacio. Universidad Nacional de Río Negro; Argentina Fil: Bauluz Lázaro, Blanca. Universidad de Zaragoza; España Fil: Canudo, José I. Universidad de Zaragoza; España Fil: Fernández, Arturo. Asociación de Amigos del Museo de Enciso; España Fil: Pérez Lorente, Félix. Universidad de La Rioja; España Here we describe the new fossil site of El Horcajo in the vicinity of Trevijano (La Rioja, Spain). It is located in the palustrine facies of the Enciso Group (Cameros Basin). This new locality has provided dozens of eggshell fragments, together with other vertebrate remains and charophyte fructifications, which allow dating of the locality as Valanginian-Hauterivian. Five ootaxa have being recognized: 1) the Spheroolithidae Guegoolithus turolensis; 2) a surprisingly thick Prismatoolithidae indet., with certain affi nities to the oogenus Sankofa, that may represent a new oogenus and oospecies for this oofamily; 3) the Krokolithidae Krokolithes sp.; 4) recrystallized ?Testudoolithidae eggshells; and 5) ?Geckoolithidae eggshells of uncertain affi nity. This oodiversity is similar to that of other eggshell microsites. The ootaxonomic list differs from the other Iberian locality of the same age, Pochancalo 1 (Villanueva de Huerva Formation, Zaragoza) in lacking sauropod and megalosauroid theropod eggshells, but shares the presence the ornithopod and coelurosaurian theropod eggshells with other younger microsites found in similar facies. The age of the new locality has immediate consequences for the tectono-sedimentary framework of the Cameros Basin, and the new data will need to be considered in future stratigraphical works. Furthermore, the reliability of eggshells as biostratigraphic markers is questioned, and the viability of Guegoolithus as a guide fossil for the lower Barremian is rejected. En este trabajo se describe el nuevo yacimiento fosilífero de El Horcajo en las cercanías de Trevijano (La Rioja, España). Se encuentra en facies palustres dentro del Grupo Enciso (Cuenca de Cameros). Este nuevo yacimiento ha proporcionado docenas de fragmentos de cáscara de huevo, junto con otros restos fósiles de vertebrados y fructifi caciones de carofi tas, que permiten datar el yacimiento como ValanginienseHauteriviense. Se han identificado cinco ootaxones: 1) Guegoolithus turolensis, de la oofamilia Spheroolithidae; 2) un Prismatoolithidae indet. sorprendentemente grueso y con afi nidades al oogénero Sankofa, que podría corresponder a un nuevo oogénero y ooespecie; 3) Krokolithes sp. de la oofamilia Krokolithidae; 4) cáscaras recristalizadas asignables con dudas a Testudoolithidae; y 5) cáscaras de afi nidad incierta, aquí asignadas con dudas a Geckoolithidae. Esta oodiversidad es similar a la de otros microyacimientos de cáscaras de huevo. La lista ootaxonómica difi ere de la obtenida en la otra única localidad de esta edad en Iberia, Pochancalo 1 (Formación Villanueva de Huerva, Zaragoza), por la ausencia de cáscaras de huevo asignables a saurópodos y terópodos megalosauroideos, pero comparte la presencia de cáscaras de huevo asignables a ornitópodos y terópodos celurosaurios con otros yacimientos más recientes que muestran facies similares. Este nuevo yacimiento tiene consecuencias inmediatas para el marco tectono-sedimentario de la cuenca de Cameros, siendo necesario considerar estos nuevos datos en futuros estudios estratigráfi cos. Además, se cuestiona la fi abilidad del uso de cáscaras de huevo como marcadores bioestratigráfi cos, ya que los nuevos datos ponen en duda la utilidad de Guegoolithus como fósil guía para el Barremiense inferior.

Crocodiloid eggshell is considered to be one of the most conservative among amniotes. This contrasts with the high body diversity observed within the crocodylomorph lineage, which extebds from the Triassic to the present. This incongruence raises a fundamental question in palaeology: is the crocodylomorph eggshell structure that conservative, or are there variations in this structure that have been misidentified in the fossil record or remain undiscovered to taphonomic biases? In this paper we re-examine eggshells from the Barremian of northern Spain that were previously assigned to chelonians. We erect a new oogenus and oospecies, Mycomorphoolithus kohringi , characterized by thin eggshells with mushroom-shaped or inverted cone shell units with blocky extinction with smooth or slightly undulating outer surface, covered by a highly variable number of pores of irregular size and shape. These variations in the pore opening pattern are here interpreted as evidence of degradation of the eggshell during embryo development, a process that has only been described in modern alligatorids. After discarding its chelonian and dinosaurian affinities, we identify them as related to Krokolithidae, but with enough differences to justify exclusion from this oofamily. In addition, eggshells from the Berriasian of England previously reported as dinosaurian-spherulitic eggshells, are here assigned to undetermined oospecies of Mycomorphoolithus . Thus, the record of Mycomorphoolithus extends throughout most of the Lower Cretaceous. This long-surviving oogenus may represent eggshells of the non-eusuchian crocodylomorphs that are abundant in the microfossil sites where Mycomorphoolithus eggshells are found.

An enlarged theropod manual ungual (CSC1-4) from the Weald facies of Spain is described. The claw was found in the fossil locality of Cana Seca 1, Teruel province, within the El Castellar Formation of early Barremian (Early Cretaceous) in age. CSC1-4 is morphologically closer to megalosauroids than to any other theropod clade bearing enlarged manual claws and shows the greatest similarity to the manual ungual of digit I of Baryonyx walkeri. Both CS1-4 and this taxon share a particularly enlarged, elongated and transversely wide manual claw. CSC1-4, however, differs from Baryonyx's ungual in having less curvature, a straight dorsal edge in the proximal part, slightly more width above the grooves than below, and a certain asymmetry, with the lateral face more flattened. Taking into account the palaeogeographic and temporal context, these considerations suggest that they are closely related but distinct spinosaurid taxa. The presence of an enlarged manual claw in spinosaurids has been invoked as an anatomical feature typically associated with scavenging and hunting habits, as well as digging behaviour. The spinosaurid record from the Barremian of the Iberian Peninsula shows that members of this clade favored freshwater environments with some marine influence in this part of Europe.

Spalacotheriids, basal trechnotheres with an acutely angled, reversed-triangle pattern of major molar cusps, are relatively rare pan-Laurasian mammals that ranged through much of the Cretaceous but are generally not well represented in the fossil record. Herein we describe newly collected specimens from the Molino Alto 1 locality, Teruel Province, Spain, and review previously described materials from the nearby locality of Galve; the sites lie in the same horizon in the upper El Castellar Formation and are of early Barremian age. On this basis, we recognize and name Aliaga molinensis, gen. et sp. nov., and provisionally place in the same genus a previously described species, cf. Aliaga henkeli, comb. nov., which appears to be the largest known spalacotheriid. The two species are characterized by a distinctive, multicuspate cingulid on lower cheek teeth. Based on acuteness of molar cusp triangulation and other features (e.g., planar molar shearing surfaces, elongation and cusp pattern of penultimat...

New fossils from the lower Barremian (Lower Cretaceous) of Spain increase the known occurrence of iguanodont dinosaurs (i.e. members of the clade Iguanodontia) in the Iberian Peninsula. A partial dentary and ischium from the fossil locality of La Cantalera 2 (Blesa Formation, municipality of Josa, Teruel province) testify to the presence of a new specimen in the early Barremian of Iberia, closely related to Delapparentia turolensis, which was previously only known in the type locality (La Maca-3, Camarillas Formation, municipality of Galve, Teruel province). These new fossils are assigned to Delapparentia turolensis (ischium) and cf. Delapparentia sp. (dentary). Moreover, the description and comparison of some of the characters of the ischium reveal that this bone is of previously unnoticed relevance for iguanodont systematics. The differences in overlapping postcranial material – observed by comparing ischial material from the provinces of Teruel and Burgos – lead us to conclude that late Hauterivian-early Barremian iguanodont diversity in Iberia consists of at least two different taxa: Delapparentia turolensis and another form closely related to Iguanodon. Additionally, dental morphotypes from La Cantalera bonebed evince the presence of at least three different iguanodonts in the lower Barremian of Iberia.

Sequence-stratigraphic, biostratigraphic and strontium-isotopic data have made it possible to update what is known of the stratigraphy and sedimentary evolution of the Kimmeridgian–Berriasian synrift successions recorded in four subbasins (Aguilon, Oliete, Morella, Galve) of the central Iberian Rift System (NE Spain). The studied successions are arranged in three unconformity-bounded synrift sequences. Synrift sequence 1A (Kimmeridgian–mid-early Tithonian) includes four transgressive-regressive sequences deposited on low-angle carbonate ramps, characterized by shallow-water grain-supported facies and coeval open-marine rhythmic successions of marls and lime mudstones (overall thickness ranging from 120 to 250 m). Ammonite biostratigraphy, combined with the last occurrence of Alveosepta jaccardi (Schrodt) and strontium-isotopic data constrains the Kimmeridgian-Tithonian boundary towards the uppermost part of synrift sequence 1A. Synrift sequence 1B (mid-early Tithonian to mid-Berriasian) consists of coastal to shallow-marine carbonate to mixed carbonate-siliciclastic successions, with a continuous record in the depocentral areas of the Morella and Galve subbasins (up to 365 m in thickness). Anchispirocyclina lusitanica (Egger) is common in the lower and middle part of the sequence, whereas charophytes of the lower Berriasian Globator maillardii maillardii Zone are recorded in its upper part. Strontium-isotopic data and ostracods whose first occurrence is Berriasian, indicate that the Tithonian-Berriasian boundary is located towards the mid-upper part of the synrift sequence 1B. Synrift sequence 1C (mid-Berriasian–mid-early Valanginian) is locally recorded in the Galve subbasin and consists of siliciclastic continental successions (up to 100 m in thickness). The available biostratigraphic data (charophytes, ostracods, sporomorphs) indicate that this sequence was deposited upwards from early Berriasian Globator maillardii incrassatus Zone. The presence of the lower Valanginian successions at the upper part of synrift sequence 1C in certain subsiding areas of the Galve subbasin cannot be ruled out. The sequence-stratigraphic and biostratigraphic data reported here indicate that the Galve and Morella subbasins started to develop during the Kimmeridgian. Successive stages of tectonic activity affected these subbasins during the mid-early Tithonian, the mid-Berriasian, and around the Berriasian-Valanginian transition. The stratigraphy and tectono-sedimentary evolution of the central Iberian Rift System indicate that the Berriasian successions are linked to the “Jurassic cycle”.

The Upper Cretaceous outcrops of the Pyrenees yield one of the most extensive and continuous records of paleoological remains anywhere in the world. Most of eggs and eggshells have been referred to...

This paper describes the skull of the eusuchian Allodaposuchus subjuniperus sp. nov. This new skull was recovered between the villages of Beranuy and Serraduy del Pon (Huesca, Spain). Stratigraphic...

A partially articulated postcranial skeleton of a small ornithischian dinosaur, Gideonmantellia amosanjuanae nov. gen. et sp., from the Early Cretaceous of Galve (Teruel province, Spain) is described. It was recovered in an outcrop of fluvial red clays from the Camarillas Formation, which is Barremian in age. This partial skeleton is recognised as a new ornithopod taxon by the following autapomorphies: (1) postacetabular process of the ilium with a brevis shelf that is noticeably medially expanded in its cranial part but narrow and horizontal in its caudal part; (2) rod-like prepubic process with its anterior end twisted and expanded; and (3) L-shaped first chevron. Our phylogenetic analysis indicates that Gideonmantellia represents a basal ornithopod taxon more derived than Orodromeus , the “Asian clade” (which includes Haya and others) and Hypsilophodon .

The sauropodAragosaurus ischiaticusSanz, Buscalioni, Casanovas & Santafé, 1987 was the first dinosaur to be described in Spain. The holotype was recovered from the site of Las Zabacheras (Galve, Teruel province). This site has traditionally been situated in the El Castellar Formation (in the lower part of the Wealden facies). Recently, it has been proposed that the remains ofAragosaurusstem from the Villar del Arzobispo Formation (late Tithonian–upper part of the early Berriasian), which would mean that the sauropod was almost 15 million years older than previously thought. Detailed field work has been carried out, making it possible to pinpoint the position of the low-angle unconformity between the Villar del Arzobispo Formation and the El Castellar Formation. This unconformity originated as a result of block tilting that occurred during the early stages of the Early Cretaceous rifting episode. The upper levels of the Jurassic sequence (i.e. the Villar del Arzobispo Formation) were exposed to erosion and karstification, leading to the formation of a discontinuous conglomeratic level. This level has been locally preserved at the bottom of the Wealden syn-rift sequence (i.e. the El Castellar Formation). The results of our detailed mapping demonstrate that theAragosaurusholotype was found in the lower part of the El Castellar Formation. Moreover, our revision of the existing datings suggests that the El Castellar Formation as a whole is Valanginian?–early Barremian in age. Given thatAragosauruswas located in its lower part, it is probably Valanginian?–Hauterivian in age.

Cuenca-Bescos, G., Badiola, A., Canudo, J.I., Gasca, J.M., and Moreno-Azanza, M. 2011. New dryolestidan mammal from the Hauterivian—Barremian transition of the Iberian Peninsula. Acta Palaeontologica Polonica 56 (2): 257–267.

A review of the stratigraphy of the Galve sub-basin (western Maestrazgo Basin, eastern Spain) around the Jurassic-Cretaceous transition is presented here, based on new data acquired after extensive geological mapping and logging complemented with facies analysis, new biostratigraphic data and a revision of the published information available. The results obtained are relevant for a more detailed understanding of the tecto-sedimentary evolution of the studied basin during the transition between two stages of rift evolution (i.e., syn-rift sequences 1 and 2). In addition, new information on the age and setting of numerous dinosaur fossil- and track-sites found across the Galve sub-basin and in the northern part of the nearby Penyagolosa sub-basin is provided here. Two new lithostratigraphic units are defined and characterized, the Aguilar del Alfambra and the Galve formations. The previous stratigraphic framework considered only two lithostratigraphic units (the Villar del Arzobispo and El Castellar formations) bounded by a single regional unconformity, and this resulted in significant misinterpretations. The whitish limestones, red lutites and cross-bedded sandstones of the Aguilar del Alfambra Formation were deposited in transitional environments, ranging from coastal lutitic plains to restricted lagoons. Of particular interest are the laminated micritic-peloidal limestones with abundant fenestral porosity (supratidal ponds to intertidal flats), which preserve common dinosaur footprints. This unit is bounded by widespread unconformities and is of very variable thickness (0-450 m), controlled by extensional tectonics operating at the climax of syn-rift sequence 1 during the latest Tithonian-middle Berriasian. The overlying Galve Formation is of variable thickness (from 0 to 100 m) and is also bounded by regional unconformities described in detail here. It consists of red lutites with cross-bedded and tabular-burrowed sandstones representing channel and overflow deposits in an alluvial floodplain. The sauropod dinosaur Aragosaurus ischiaticus found in this unit has a controversial age assignment. The age of the Galve Formation is poorly constrained from late Berriasian to Hauterivian, but new biostratigraphic data presented here, combined with the correlation with the nearby Penyagolosa and Salzedella sub-basins, suggest a possible equivalence to the upper Berriasian-lower Valanginian sequence deposited during the initial stage of syn-rift sequence 2. Fil: Aurell, Marcos. Universidad de Zaragoza; España Fil: Bádenas, Beatriz. Universidad de Zaragoza; España Fil: Gasca Pérez, José Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Zaragoza; España Fil: Canudo, José I.. Universidad de Zaragoza; España Fil: Liesa, Carlos L.. Universidad de Zaragoza; España Fil: Soria, Ana R.. Universidad de Zaragoza; España Fil: Moreno Azanza, Miguel. Universidad de Zaragoza; España Fil: Najes, Laura. Universidad de Zaragoza; España

The sauropod of El Oterillo II is a specimen that was excavated from the Castrillo de la Reina Formation (Burgos, Spain), late Barremian–early Aptian, in the 2000s but initially remained undescribed. A tooth and elements of the axial skeleton, and the scapular and pelvic girdle, represent it. It is one of the most complete titanosauriform sauropods from the Early Cretaceous of Europe and presents an opportunity to deepen our understanding of the radiation of this clade in the Early Cretaceous and study the paleobiogeographical relationships of Iberia with Gondwana and with other parts of Laurasia. The late Barremian–early Aptian is the time interval in the Cretaceous with the greatest diversity of sauropod taxa described in Iberia: two titanosauriforms,TastavinsaurusandEuropatitan; and a rebbachisaurid,Demandasaurus. The new sauropodEuropatitan eastwoodin. gen. n. sp. presents a series of autapomorphic characters in the presacral vertebrae and scapula that distinguish it from the other sauropods of the Early Cretaceous of Iberia. Our phylogenetic study locatesEuropatitanas the basalmost member of the Somphospondyli, clearly differentiated from other clades such as Brachiosauridae and Titanosauria, and distantly related to the contemporaneousTastavinsaurus.Europatitancould be a representative of a Eurogondwanan fauna likeDemandasaurus, the other sauropod described from the Castrillo de la Reina Formation. The presence of a sauropod fauna with marked Gondwananan affinities in the Aptian of Iberia reinforces the idea of faunal exchanges between this continental masses during the Early Cretaceous. Further specimens and more detailed analysis are needed to elucidate if this Aptian fauna is caused by the presence of previously unnoticed Aptian land bridges, or it represents a relict fauna from an earlier dispersal event.

Trigonoolithus amoae oogen. et oosp. nov. is described on the basis of abundant eggshell fragments from the La Cantalera 1 site in the Early Cretaceous (early Barremian) Blesa Formation, Teruel Province, northern Spain. The surface ornamentation, the most diagnostic feature of the new oogenus, consists of closely spaced sub-triangular or rounded protuberances that have not previously been reported in any other ootaxon. The eggshells present three distinct layers, with a gradual transition between prismatic and mammillary layers, and a poorly developed external layer with progressive prismatic to external layer transition, a combination of characters that allows them to be assigned to Prismatoolithidae. Phylogenetic analyses based on oological characters place Trigonoolithus at the base of Prismatoolithidae.