Fossil associations from the middle and upper Eocene strata of the Pamplona Basin and surrounding areas (Navarre, western Pyrenees)

Abstract

Fossil associations from the middle and upper Eocene (Bartonian and Priabonian) sedimentary succession of the Pamplona Basin are described. This succession was accumulated in the western part of the South Pyrenean peripheral foreland basin and extends from deep-marine turbiditic (Ezkaba Sandstone Formation) to deltaic (Pamplona Marl, Ardanatz Sandstone and Ilundain Marl formations) and marginal marine deposits (Gendulain Formation). The micropalaeontological content is high. It is dominated by foraminifera, and common ostracods and other microfossils are also present. The fossil ichnoasssemblages include at least 23 ichnogenera and 28 ichnospecies indicative of Nereites, Cruziana, and ?Scoyenia-Mermia ichnofacies. Body macrofossils of about 80 taxa corresponding to macroforaminifera, sponges, corals, bryozoans, brachiopods, annelids, molluscs, arthropods, echinoderms and vertebrates have been identified. Both the number of ichnotaxa and of species (e. g. bryozoans, molluscs and condrichthyans) may be considerably higher. Body fossil assemblages are comparable to those from the Eocene of the Nord Pyrenean area (Basque Coast), and also to those from the Eocene of the west-central and eastern part of South Pyrenean area (Aragon and Catalonia). At the European scale, the molluscs assemblages seem endemic from the Pyrenean area, although several Tethyan (Italy and Alps) and Northern elements (Paris Basin and Normandy) have been recorded. Palaeontological data of studied sedimentary units fit well with the shallowing process that throughout the middle and late Eocene occurs in the area, according to the sedimentological and stratigraphical data.Se describen las asociaciones fósiles del Eoceno medio y superior (Bartoniense y Priaboniense) de la sucesión sedimentaria de la Cuenca de Pamplona. Esta sucesión se acumuló en la parte oeste de la Cuenca de antepaís periférica surpirenaica y comprende desde turbiditas marinas profundas (Formación Areniscas de Ezkaba) hasta depósitos deltaicos (Formaciones Margas de Pamplona, Areniscas de Ardanatz y Margas de Ilundain) y marinos marginales (Formación Gendulain). El contenido micropaleontológico es alto y está dominado por los foraminíferos. Los fósiles de ostrácodos y otros organismos son también abundantes. Las asociaciones de icnofósiles incluyen al menos 23 icnogéneros y 28 ichnoespecies, indicativas de las icnofacies de Nereites, Cruziana, y ?Scoyenia-Mermia. Se han identificado fósiles corporales de unos 80 taxones, correspondientes a macroforaminíferos, esponjas, corales, briozoos, braquiópodos, anélidos, moluscos, artrópodos, equinodermos y vertebrados. El número de icnotaxones y de especies (p. e. briozoos, moluscos gasterópodos, bivalvos y peces condríctios) puede ser considerablemente mayor. Las asociaciones de fósiles corporales son comparables a las del Eoceno del Área norpirenaica (Costa vasca) y de las partes central y este del Área surpirenaica (Aragón y Cataluña). A escala europea, la asociación de moluscos parece endémica del Área pirenaica,...

The most representative vertebrate fossil record and palaeontological heritage from the western Pyrenees

“…All the remains are well preserved and were provisionally attributed to the Dugongidae; it cannot be ruled out that the fossils correspond to a basal dugongid close to the genus Prototherium. The vertebral series belonging to the same individual and found in Ardanatz come from the deposits in the transition between the Ardanatz Sandstone and the Ilundain Marl formations, are early Bartonian in age, and were interpreted as corresponding to a restricted marine platform with locally abundant macrofossil invertebrate associations (Astibia et al, 2016). Near Uztarrotz, in the Pamplona Marl Formation, which is situated below stratigraphically than the above-mentioned formations, around thirty sirenian remains were found in prodelta deposits.…”

Gastropods and bivalves from the Eocene marly formations of the Pamplona Basin and surrounding areas (Navarre, western Pyrenees)

“…Medium and large-sized species, alongside some smaller species, are herein reported, whereas the study of most small-sized species is pending. Most of the molluscs seem to be endemic to the Pyrenean area, although several species from the Tethyan (Italy and Alps) and Northern (Paris Basin and Normandy) domains have also been recorded (Astibia et al 2016), thus confirming the role of the Pyrenean area in connecting the two domains. The results exposed herein will further contribute to enlarge the database for a better understanding of faunal gradients and the evolution of global marine biodiversity throughout the Eocene.…”

“…Body macrofossils are locally abundant in the Ardanatz Sandstone and Ilundain Marl formations. The macrofauna is mainly represented by macroforaminifera, hexactinellid and lithistid sponges, scleractinian corals, bryozoans, brachiopods, tube-dwelling polychaetes, molluscs (gastropods, bivalves, cephalopods and scaphopods), arthropods (crustaceans), echinoderms (crinoid stalk fragments, plates -ossicles -of asteroids, and spines and test fragments of echinoids), shark teeth, turtle plates as well as sirenian vertebrae and ribs (Calzada & Astibia 1996;Astibia et al 1999Astibia et al , 2005Astibia et al , 2006Astibia et al , 2014Astibia et al , 2016Buffrénil et al 2008;Bitner et al 2016).…”

El anélido Rotularia spirulaea (Lamarck, 1818) (Polychaeta, Serpulidae) de las margas del Eoceno de la Cuenca de Pamplona (Navarra): microestructura, tafonomía y paleoecología

“…Lamarck 2008-14). R. spirulaea es también abundante en muchos enclaves del Eoceno marino del área surpirenaica, desde la región de Vic (Bartoniense-Priaboniense, noreste de la Cuenca del Ebro) (Abad, 2001), siguiendo hacia el este por la Cuenca de Jaca, hasta alcanzar la Cuenca de Pamplona y zonas colindantes (Bartoniense y Priaboniense, suroeste de los Pirineos) (Astibia et al, 2016b), de cuyas extensas formaciones margosas, provienen los materiales descritos en este trabajo. R. spirulaea es también reconocida en el dominio del Tetis: Italia (Savazzi, 1995;Vinn, 2008), Croacia (Mikuž, 2008), Hungría (Fozy & Szente, 2014) y Península de Anatolia (Hoşgör & Okan, 2006).…”

“…R. spirulaea también está presente en los niveles del Bartoniense de la cercana área navarra de la Sierra de Urbasa, existiendo ejemplares de este fósil no publicados en la colección Ruiz de Gaona. La presencia de R. spirulaea en la zona de este estudio fue nuevamente constatada por Astibia et al (2014Astibia et al ( , 2016b, siendo localmente abundante en niveles margosos de las formaciones denominadas Areniscas de Ardanatz y Margas de Ilundain, en asociación con otros muchos macrofósiles (corales, briozoos, moluscos, equinodermos y otros grupos) (véase apartado 2).…”