Cenomanian transgression in the Basque-Cantabrian Basin (northern Spain) and associated faunal replacement

Abstract:The available data concerning the environmental changes and faunal replacements that occurred during the Cenomanian marine transgression in the North of Iberia are integrated and discussed on the basis of new evidence from the invertebrate and vertebrate fossil record. New stratigraphical data and the reassessment of known stratigraphic sections support the correlation of the Cenomanian carbonate-ramp successions from the Iberian margin to the centre of the Basque-Cantabrian Basin during a major transgressive episode. This new stratigraphical framework is the key to understand the changing oceanographic conditions in the area that resulted from a progressive inundation of the Iberian continental platform. This transgression seems to have triggered major faunal replacements in this particular geographic area, starting out around the Albian-Cenomanian transition. Ammonite faunal replacement led to a new radiation of this group that spread out rapidly until their new decline around the Cenomanian-Turonian boundary. A new record of Calycoceras (Newboldiceras) asiaticum spinosum and the first record of a Pachyrhizodontidae indet. (Actinopterygii, Teleostei, Crossognathiformes) from the Iberian Peninsula are reported here from the Cenomanian basal units of the major Late Cretaceous transgressive episode. The two new specimens come from the same level in an outer marine ramp succession near Amurrio, Basque Country, northern Spain, and are representatives of the Cenomanian faunal turnover. The new record of a pachyrhizodontoid fish from the Cretaceous of Iberia is an indication of the ichthyofaunal replacement in this part of the world. The relict fish faunas from the Early Cretaceous of the former island of Iberia were mostly formed by basal neopterygian taxa closely related to those of the marine Jurassic of other parts of Europe. During the Early-Late Cretaceous transition they were replaced by the teleostean-based new stock that constitutes the basis of the Late Cretaceous, Cenozoic, and Recent faunas.Resumen: Se integran y discuten los datos disponibles sobre los cambios ambientales y los reemplazamientos faunísticos que sucedieron en el norte de Iberia durante la transgresión del Cenomaniense, incluyéndose nuevas evidencias de los registros fósiles de invertebrados y vertebrados. Nuevos datos estratigráficos y la revisión de secciones estratigráficas conocidas proporcionan fundamentos para la correlación de las series de rampa carbonatada cenomanienses desde el margen ibérico hasta la zona central de la Cuenca Vasco-Cantábrica, desarrolladas durante un importante episodio transgresivo. Este nuevo esquema estratigráfico configura la base para entender las cambiantes condiciones oceanográficas en la zona de estudio, las cuales resultaron de una progresiva inundación del margen continental ibérico. Esta transgresión se vislumbra como factor determinante para reemplazamientos faunísticos en esta zona, que comenzaron durante el tránsito Albiense-Cenomaniense. Los cambios en las faunas de ammonites condujeron hacia una rápida radiación del grupo hasta un nuevo declive alrededor del tránsito Cenomaniense-Turoniense. Se describen aquí un nuevo registro de Calycoceras (Newboldiceras) asiaticum spinosum y el primer registro de Pachyrhizodontidae indet. (Actinopterigii, Teleostei, Crossognathiformes) de la Península Ibérica, provenientes de la parte basaldel episodio transgresivo cenomaniense. Ambos son representativos del cambio faunístico y proceden del mismo nivel estratigráfico en una serie de rampa carbonatada externa cerca de Amurrio, País Vasco, España. Asimismo, este primer Pachyrhizodontoidei del Cretácico de Iberia indica un cambio importante en las faunas de teleósteos en esta parte del mundo. Las faunas relictas de peces del Cretácico inferior de la entonces isla de Iberia estaban básicamente compuestas por neopterigios basales directamente relacionados con los del Jurásico marino de otras partes de Europa. Durante la transición Cretácico Inferior-Cretácico Superior fueron paulatinamente reemplazados por nuevos grupos de teleósteos, los cuales constituyen la mayor parte de las formas del Cretácico Superior, del Cenozoico y actuales

Tafonomía y paleoecología del ecosistema acuático de Las Hoyas (Barremiense superior, Serranía de Cuenca).

The freshwater ecosystem of Las Hoyas contains one of the most significant records of aquatic organisms described from the Early Cretaceous worldwide. The benthos was formed by a diverse assemblage of animals such as aquatic insects, ostracods, cray-fishes, and juvenile and small adult fishes, which depended on the ground cover of charophytes and aquatic angiosperms for shelter and food. The nekton was mainly composed o f crustaceans and a large variety of fishes. Phytoplankton is represented by two chlorophytes and zooplankton is represented by planktonic pupae of dipterans. Cheirolepidiaceous conifers, matoniaceous tree-ferns and herbaceous schizaeacean ferns were growing in swamps. Among tetrapods with aquatic habitats modern amphibians and reptiles were found. In spite of the exceptional preservation, the fossil record of Las Hoyas includes sedimentological, taphonomic and palaeoecological biases. Form the palaeoecological point o f view, mass mortality levels contain thousands of individuals of crayfish associated with freshwater plant remains. These levels are attributed to eutrophication events of the otherwise oligotrophic lake. Other mass-mortality levels include hundreds of juvenile teleostean individuals associated with small shrimps. Changes in the water-table and related temperature changes, variation of acidity or input of toxic substances may account for this type of mass mortality

Taphonomy

Trabajo presentado en el II International Symposium on Lithographic Limestones celebrado en Cuenca.-- Field trip guide book.The taphonomic anal ysis of the Las Hoyas site is still at an early stage. This analysis is necessary since it is considered a prerequisite for paleoecological reconstructions (Shipman, 1981). Besides, taphonomic analysis has its own aims; in this case they could be summarized as the establishment of the temporal succession of processes which led to the formation of the site.Peer reviewe

Late cretaceous continental and marine vertebrate assemblages of the Laño Quarry (Basque-Cantabrian Region, Iberian Peninsula): An update

The vertebrate-bearing beds of the Laño quarry (Condado de Treviño) are among the most relevant sites from the Late Cretaceous of Europe. Geologically, Laño and the adjacent region are set on the southern limb of the South-Cantabrian Synclinorium (SE Basque-Cantabrian Region, northern Iberian Peninsula). The Laño sites were discovered in 1984; thousands of bones and teeth, including microfossils, have been collected during the prospection in the field and excavation campaigns. The vertebrate remains occur at two different stratigraphic horizons within a continental to shallow marine succession of Late Campanian-Maastrichtian age. The lower horizon contains the Laño 1 and Laño 2 sites, whereas the upper horizon contains the Albaina site. In the Laño sites, three fossiliferous beds (called L1A, L1B and L2) are known within an alluvial system composed mainly of fluvial sands and silts. The sedimentary structures are consistent with channel areas within an extensive braided river system. Based mainly on stratigraphic correlations, the fluvial beds of Laño are regarded as Late Campanian to Early Maastrichtian in age. These deposits have yielded a very diverse vertebrate assemblage, which consists of nearly 40 species, including actinopterygians, lissamphibians, lepidosaurs, turtles, crocodyliforms, dinosaurs, pterosaurs, and mammals. Seven genera and ten species have been erected to date in Laño. With reference to the marine vertebrate association of Albaina, it consists of at least 37 species, including sharks and rays, actinopterygians, mosasaurids, and plesiosaurs. Two genera and species of rhinobatoids (family indet.) and two new species of rhinobatids have been erected in Albaina. The fossil association indicates a Late (but not latest) Maastrichtian age. Recently, isolated turtle and dinosaur fossils have been discovered in the sublittoral beds of Albaina. The Laño quarry is one of the most noteworthy Campanian-Maastrichtian vertebrate localities of Europe by its taxonomic diversity, and provides useful information about the composition and affinities of both continental and marine vertebrate faunas from the latest Cretaceous of southwestern EuropeLos niveles con fósiles de vertebrados de la cantera de Laño (Condado de Treviño) se cuentan entre los más importantes del Cretácico Superior de Europa. Desde un punto de vista geológico, Laño y la región adyacente forman parte del flanco sur del Sinclinorio Subcantábrico (SE de la Región Vasco-Cantábrica). El descubrimiento de los niveles fosilíferos remonta a 1984; las prospecciones de campo y las campañas de excavación han proporcionado miles de huesos y dientes, incluyendo microfósiles. Los restos de vertebrados aparecen en dos horizontes estratigráficos diferentes formando parte de una sucesión continental a marina litoral de edad Campaniense superior a Maastrichtiense. El horizonte inferior contiene los yacimientos de Laño 1 y Laño 2, mientras que el superior contiene solo uno: Albaina. En los yacimientos de Laño, se reconocen tres niveles fosilíferos (llamados L1A, L1B y L2) formados en el seno de un sistema aluvial compuesto por arenas y limos fluviales. Las estructuras sedimentarias indican áreas de canal dentro de un sistema trenzado muy extendido. Según las correlaciones estratigráficas, los depósitos fluviales de Laño son de edad Campaniense superior a Maastrichtiense inferior. Estos depósitos han proporcionado una asociación muy diversa de vertebrados, que consiste en cerca de 40 especies, incluyendo actinopterigios, lisanfibios, lepidosaurios, tortugas, cocodrilos, dinosaurios, pterosaurios y mamíferos. En Laño se han definido hasta el momento siete géneros y diez especies. Por lo que respecta a la asociación de vertebrados marinos de Albaina, se han reconocido al menos 37 especies, que incluyen tiburones y rayas, actinopterigios, mosasaurios y plesiosaurios. Hasta la fecha se han definido en Albaina cuatro nuevos rinobatoideos: dos especies de rinobátidos y dos géneros y especies cuya familia es indeterminada. La asociación fósil es de edad Maastrichtiense superior no terminal. Recientemente se ha descrito el hallazgo de restos fósiles aislados de tortugas y dinosaurios en los niveles marinos de Albaina. La cantera de Laño es una de las localidades de vertebrados más destacadas del Campaniense-Maastrichtiense por su diversidad taxonómica, y proporciona información relevante sobre la composición y afinidades de las faunas de vertebrados continentales y marinos del Cretácico final del suroeste de EuropaField research in the Laño quarry has been supported by financial aids of the Ministerio de Economía y Competitividad (MINECO projects CGL2010-18851/BTE and CGL2013-47521-P), Ministerio de Ciencia e Innovación (CGL2007-64061/BTE), Ministerio de Ciencia y Tecnología (CGL2004-02338/BTE, BTE2001-0185-C02-01, BOS2000-1369), Ministerio de Educación y Ciencia (Acción Integrada hispano-francesa 201-B), Diputación Foral de Álava/Arabako Foru Aldundia (93/23, 95/A23), Gobierno Vasco/Eusko Jaurlaritza (IT834-13, IT-320-10, IT-361-07, GV121.310-4/87), Universidad del País Vasco/Euskal Herriko Unibertsitatea (9/ UPV00121.310-15303/2003), Centre National de la Recherche Scientifique (CNRS, France), Institut National des Sciences de l’Univers (INSU), The Dinosaur Society (research grant 1997) and the National Geographic Research (grant #6597-99). This work is part of a palaeontological collaboration (Convenio específico de colaboración) between the Universidad del País Vasco/EHU, the Centre National de la Recherche Scientifique (CNRS, France) and the Muséum National d’Histoire Naturelle (MNHN, Paris). Contribution ISEM n° 2015-04

Il Cretacico Inferiore di Las Hoyas

Il giacimento fossilifero di Las Hoyas fu scoperto agli inizi degli anni '80 dal dilettante delluogo Armando Díaz Romeral e dal geologo Santiago Prieto (Prieto e Díaz Romeral1989). Essi notarono che le lastre di calcare che provenivano da affioramenti della regione, e che erano utilizzate per rivestimenti e lastricati, contenevano a volte dei fossili. I primi lavori su! campo furo no effettuati nell' esta te del 1985, e da quella data sono stati scoperti all'incirca 8.000 esemplari. Tutti gli esemplari sono attualmente inseriti in una banca dati computerizzata.Peer reviewe

Die Unter-Kreide von Las Hoyas, Cuenca

Meischner D. (eds).Die Fossilfundstätte Las Hoyas wurde zu Beginn der 80er Jahre durch den örtlichen Privatsammler Armando Díaz Romeral und den Geologen Santiago Prieto entdeckt (Prieto et Díaz-Romeral 1989). Sie bemerkten Fossilien in Kalkstein-Platten, die zum Bau von Mauern und Fusswegen verwandt wurden. Die ersten Arbeiten im Aufschluss wurden im Sommer 1985 unternommen. Seither sind einige 8000 Fossilien geborgen worden. Zusätzlich zu den Körperfossilien, die in diesem Artikel genannt werden, wurden Spurenfossilien von Invertebraten und Vertebraten gesammelt (Moratalla et Fregenal-Martínez 1995). Das meiste Material, das dem Museo de Cuenca gehört, ist vorläufig an der Unidad de Paleontologia, Universidad Autónoma de Madrid (UAM) untergebracht.Peer reviewe

A new semionotiform actinopterygian fish from the Mesozoic of Spain and its phylogenetic implications

<div><p><i>Camerichthys lunae</i> gen. et sp. nov. is a semionotiform actinopterygian fish described from the newly reported locality of San Andrés de San Pedro (province of Soria, Spain). The material, an articulated, partial three-dimensional specimen, was unearthed from the Tithonian–Berriasian beds of the Matute Formation (Tera Group) in the continental Cameros Basin. The new taxon, <i>Camerichthys lunae</i> gen. et sp. nov., differs from other ginglymodians in presenting a unique combination of characters plus: presence of a suprapreopercular bone; antorbital intermediate in depth in relation to the other anterior infraorbitals; and infraorbital placed in the anterior border of the orbit subdivided into two portions (three uniquely derived characters). The results of the cladistic analysis show that the new genus from Soria cannot be assigned to any of the three semionotiform families, Callipurbeckiidae, Macrosemiidae or Semionotidae. It is considered Semionotiformes <i>incertae sedis</i>. In the more resolutive analysis, with ordered characters, <i>Camerichthys lunae</i> gen. et sp. nov. appears as the sister group of the clade formed by the families Callipurbeckiidae plus Macrosemiidae. The effects of the new genus on the phylogeny of these two families and <i>Dapedium</i>, <i>Semionotus</i> and <i>Paralepidotus</i>, are discussed. <i>Camerichthys</i> gen. nov. is the first ginglymodian genus endemic to the Iberian Peninsula.</p><p>http://zoobank.org/urn:lsid:zoobank.org:pub:BBD15A41-5BFC-4BFF-AD40-ECD1891953F1</p></div

Tidal facies with vertebrate remains in a transgressive setting: Calizas de la Bicuerca Mb., (Albian-Cenomanian) Serranía de Cuenca, Iberian Basin

El análisis de las facies del Mb. Calizas de la Bicuerca (Albiense-Cenomaniense) en el ámbito de la Cuenca Ibérica Suroccidental y las relaciones existentes entre ellas sitúa el depósito de estos materiales en un ambiente mareal durante un contexto transgresivo. El muestreo de una de las secciones ha dado lugar al hallazgo de un fragmento de dentición vomeriana atribuible a un pez óseo actinopterigio del orden Pycnodontiforme. Este ejemplar supone el primer hallazgo de restos vertebrados identificables en esta unidad.Analyses of the sedimentary facies and their geometrical relation indicate a tidal environment for Calizas de la Bicuerca Mb. (Albian-Cenamanian) during a transgressive setting. A vomerine dentition was unearthed during surface sampling of one stratigraphic section. This vomerine dentition has been assessed to the actinopterigian fish order Pycnodontiformes. This specimen is the first assessable vertebrate remain from this unit.Ministerio de Educación y Ciencia.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu