Conulus sanzgarciai sp. nov. (Echinodermata: Echinoidea) from the lower Aptian of Coratxà (Maestrat Basin)

Dins del projecte general de l’estudi sistemàtic dels equinoïdeus de la conca del Maestrat es descriu una espècie nova, Conulus sanzgarciai sp. nov., de la família Conulidae Lambert, 1911. L’espècie s’ha trobat a Coratxà (el Baix Maestrat; País Valencià), i pertany a la formació Margues del Forcall, membre Morella la Vella, datat com Aptià inferior. Amb aquesta espècie nova s’amplia l’escàs registre fòssil conegut del gènere per al Cretaci Inferior.Within the overall project for the systematic study of the echinoids from the Maestrat Basin, a new species, Conulus sanzgarciai sp. nov., family Conulidae Lambert, 1911, is described. The species has been found in Coratxà (el Baix Maestrat, País Valencià) belonging to the Forcall Formation, Morella la Vella Member, dated as lower Aptian. With this new species, the limited fossil record of the genus for the Lower Cretaceous is expanded

Conulus sanzgarciai sp. nov. (Echinodermata: Echinoidea) de l’Aptià inferior de Coratxà (conca del Maestrat)

Conulus sanzgarciai sp. nov. (Echinodermata: Echinoidea) from the lower Aptian of Coratxà (Maestrat Basin)Dins del projecte general de l’estudi sistemàtic dels equinoïdeus de la conca del Maestrat es descriu unaespècie nova, Conulus sanzgarciai sp. nov., de la família Conulidae Lambert, 1911. L’espècie s’ha trobat aCoratxà (el Baix Maestrat; País Valencià), i pertany a la formació Margues del Forcall, membre Morella laVella, datat com Aptià inferior. Amb aquesta espècie nova s’amplia l’escàs registre fòssil conegut del gènereper al Cretaci Inferior.Within the overall project for the systematic study of the echinoids from the Maestrat Basin, a new species,Conulus sanzgarciai sp. nov., family Conulidae Lambert, 1911, is described. The species has been foundin Coratxà (el Baix Maestrat, País Valencià) belonging to the Forcall Formation, Morella la Vella Member,dated as lower Aptian. With this new species, the limited fossil record of the genus for the Lower Cretaceousis expanded

Review of the early Albian ammonites of the Montmell Formation near Marmellar (Salou-Garraf Basin, Tarragona, Catalonia, Spain)

In this work, we review the ammonites of the Montmell Formation in the Marmellar area housed in the collections of the Museo Geológico del Seminario de Barcelona and the Museu de Geologia de Barcelona. This taxonomic update allows the proper biostratigraphic analysis of the ammonite assemblage and assigns it to the early Albian, Leymeriella tardefurcata Zone. The taxonomic analysis of all the studied material allows us to recognize the presence of the following taxa: Uhligella sp., Parengonoceras bassei, Hypacanthoplites plesiotypicus, Hypacanthoplites milletianus, Hypacanthoplites subelegans, and Hypacanthoplites sp. The current work is a step forward in the chronostratigraphic knowledge of the Salou-Garraf Basin in the Catalan Coastal Ranges

Mesozoic stratigraphy and new Aptian cephalopods of el Vendrell, southwest of the Garraf Massif (Catalonia)

En aquest treball es mostra l'estratigrafia del Mesozoic de l'extrem sud-oest del massís del Garraf i es dóna a conèixer per primera vegada una associació de cefalòpodes procedents de l'Aptià (Cretaci inferior) de l'entorn del municipi del Vendrell. El Mesozoic que aflora a l'est del Vendrell esta format per roques fonamentalment carbonàtiques del Kimmeridgià-Berriasià a les que se li superposen de forma discordant els dipòsits del Barremià i l'Aptià. En l'Aptià del Vendrell s'identifiquen uns ammonits i nautiloïdeus trobats a la part baixa de la unitat Margues de Vallcarca (Salas & Moreno, 2008) i se'n realitza una anàlisi biostratigràfica. També s'analitza l'estratigrafia deis materials del Cretaci inferior (Barremià superior-Aptià superior) d'aquest sector de la conca de Salou-Garraf mitjan<;:ant una correlació amb la conca veïna del Maestral. Entre els cefalòpodes estudiats destaca la presencia de l'ammonit Pseudosaynella bicurvata (Michelin, 1838), ja que és la primera vegada que aquesta espècie se cita al massís del Garraf, i un exemplar ben conservat del nautiloïdeu Heminautilus lallierianus (d'Orbigny, 1841), el segon exemplar conegut d'aquesta espècie al Garraf. Des d'un punt de vista biostratigrafic, els cefalòpodes aptians estudiats constitueixen un dels registres més antics coneguts per a la unitat Margues de Vallcarca, essent atribuïble a les biozones Deshayesites forbesi i Deshayesites deshayesi (Aptià inferior). La correlació efectuada entre les unitats litostratigràfiques del Barremià superior i l'Aptià de les conques veïnes de Salou-Garraf i del Maestrat permet assignar al Barremià terminal la part basal de la unitat Margues de Vallcarca, quan c1assicament aquesta unitat de la conca de Salou-Garraf havia estat atribuïda íntegrament a l'Aptià.The current work shows the Mesozoic stratigraphy of the southwestern part of the Garraf Massif and reports for the first time an Aptian (Lower Cretaceous) cephalopod assemblage from the surroundings of the town of el Vendrell. The Mesozoic out craps to the east of el Vendrell primarily consist of carbonate rocks of Kimmeridgian-Berriasian age, which are uncorformably overlain by Barremian and Aptian deposits. In the Aptian of el Vendrell, we identify ammonoids and nautiloids that were collected in the lower part of the Vallcarca Marls Unit (Salas & Moreno, 2008), and we carry out a biostratigraphic analysis. We also analyze the stratigraphy of the Cretaceous materials (upper Barremian to upper Aptian) of this area of the Salou-Garraf Basin and establish a correlation with the neighboring Maestrat Basin. Among the cephalopods studied, the presence of the ammonite Pseudosaynella bicurvata (Michelin, 1838) is remarkable because it is the first time that this species is quoted in the Garraf Massif. In addition, we report a well-preserved specimen of the nautiloid Heminautilus lallierianus (d'Orbigny, 1841), which is the second specimen of this species known in the Garraf area. Fram a biostratigraphic point of view, the Aptian cephalopods studied herein are some of the oldest known records of the Vallcarca Marls Unit being attributed to the Deshayesites forbesi and Deshayesites deshayesi biozones (lower Aptian). The correlation between the upper barremian and Aptian lithostatigraphic units among the neighboring basins Salou-Garraf and Maestrat allows us to ascribe for the first time the basal part of the Vallcarca Marls Unit to the uppermost Barremian. This latter lithostatigraphic unit of Salou-Garraf Basin has been classically attribued to the Aptian

Révision des ammonites aptiennes étudiées par Burckhardt en 1906 et provenant de Mazapil, État de Zacatecas (centre nord du Mexique)

Twelve specimens of Aptian ammonites reported and drawn by Burckhardt in 1906, from the Mazapil area (Zacatecas State, north-central Mexico), are reviewed for taxonomical purposes. The work by Burckhardt was the first report of Aptian ammonoids in Mexico. In addition, it represents the only record of Aptian ammonites known from Zacatecas State. The taxonomic review of the specimens allows for the recognition of Dufrenoyia sp., Colombiceras spathi Humphrey, Colombiceras mexicanus (Humphrey) n. comb., Colombiceras sp., Colombiceras spp., and Acanthohoplites aff. bigoureti (Seunes). This ammonite assemblage is indicative of a stratigraphic range that spans the uppermost lower Aptian to the upper Aptian interval.Douze exemplaires d'ammonites aptiennes, provenant de la région de Mazapil (État de Zacatecas, centre nord du Mexique), signalées et illustrées par Burckhardt en 1906, sont révisées à des fins taxinomiques. Ce travail de Burckhardt constitue le premier rapport mentionnant des ammonoïdés aptiens au Mexique. Il s'agit, en outre, du seul compte-rendu portant des ammonites aptiennes récoltées dans l'État de Zacatecas. La révision taxinomique de ces exemplaires permet l'identification de Dufrenoyia sp., Colombiceras spathi Humphrey, Colombiceras mexicanus (Humphrey) n. comb., Colombiceras sp., Colombiceras spp. et Acanthohoplites aff. bigoureti (Seunes). Cette association d'ammonites est représentative d'un intervalle stratigraphique s'étendant de la partie sommitale de l'Aptien inférieur à l'Aptien supérieur

Glaucoceras gen. nov., a small uncoiled ammonoid from the Tethyan late Hauterivian (Early Cretaceous) : evolutionary implications at the dawn of the diversification of heteromorphic lineages

The poorly-known species Baculites Renevieri Ooster, 1860 is revised using the type material from Switzerland and new conspecific specimens collected in deposits from Mallorca and the Betic Cordillera (Western Mediterranean), listing all the previous mentions of the species. The uniqueness of its ornamentation pattern and shell shape compared to other coeval ammonoid faunas demands for the description of Glaucoceras gen. nov. to contain this species. In addition, a thorough comparison of Glaucoceras renevieri to other morphologically reminiscent genera or species is provided. This new set of data allows to improve the knowledge of one of the many phylogenetic lines of heteromorphic ammonites that diversified over the latest Hauterivian in the Mediterranean Province, also providing hints about the timing of those radiation events. This aspect is preliminary explored using data on other coeval heteromorphic ammonoid groups from the literature and new finds, concluding that there occurred two main radiation events of heteromorphic ammonites at the latest Hauterivian, most likely related to environmentally stressful episodes, specifically, transgressive events

La faune d'ammonites de la Zone à Prionocyclus germari (Turonien supérieur) de Rochefort-en-Valdaine (Drôme, France)

The late Turonian ammonoid fauna of Rochefort-en-Valdaine (Drôme, France) is herein described in detail and the intraspecific variability of Vocontiiceras vocontiense Diebold et al., 2018, is studied. The ammonoid assemblage (9 taxa identified) was deposited within the Prionocyclus germari Zone, which was defined in Germany, and is now also documented in southeastern France. Moreover, the co-occurrence of the heteromorph ammonoids Hyphantoceras (Hyphantoceras) flexuosum (Schlüter) and Hyphantoceras (Hyphantoceras) ernsti Wiese indicates the lower part of the Prionocyclus germari Zone.La faune d'ammonites du Turonien supérieur de Rochefort-en-Valdaine (Drôme, France) est décrite en détail et la variabilité intraspécifique de Vocontiiceras vocontiense Diebold et al., 2018, est étudiée. Cette faune d'ammonites (9 taxons identifiés) est caractéristique de la Zone à Prionocyclus germari, préalablement définie en Allemagne, et dont la présence est maintenant démontrée dans le sud-est de la France. De plus, la présence des ammonites hétéromorphes Hyphantoceras (Hyphantoceras) flexuosum (Schlüter) et Hyphantoceras (Hyphantoceras) ernsti Wiese indique plus précisement la partie inférieure de la Zone à Prionocyclus germari

New paleontological and stratigraphical data at the Aptian - Albian transition in the Ariege Pyrenees (France)

The discovery of ammonites of the Aptian - Albian transition (Hypacan-thoplites jacobi and Leymeriella tardefurcata biozones) in the Urgonian series from the sedimentary section exposed in the Arize massif invalidates their former attribution to the lower Clansayesian which was proposed on the basis of unconstrained paleontological arguments.La découverte d'ammonites du passage Aptien - Albien (biozones à Hypacanthoplites jacobi et à Leymeriella tardefurcata), dans la série urgonienne de la couverture du massif de l'Arize invalide l'attribution antérieure au Clansayésien inférieur proposée sur des arguments paléontologiques non contraints

Corals on the slope (Aptian, Maestrat Basin, Spain)

The term "reef" has been frequently misused when applied to fossil coral communities. Our popular but biased view of coral community structure based on the idyllic picture of recent tropical reefs has failed to recognize that, in many fossil examples, alternative states of community structure with no or limited framework may occur. The Aptian colonial scleractinians analysed in the western Maestrat Basin (eastern Spain) constitute an example of non-reef-building coral populations, which thrived in marly slope settings. These corals developed within the photic zone but below the storm wave-base. All colonies are found well-preserved in life position. They are mostly decimetres in size and mainly occur isolated giving rise to a continuous and uniform (dominated by domal and massive forms) unbound growth fabric with a low to medium degree of development (coral skeletal volume = 5-20%). Occasionally, however, colonies growing on top of each other forming small metre-sized bioherms are also present. A total of 21 species were identified. Coral diversity in each sample location varies between three and nine species. These numbers of species are comparable with those exhibited by coeval coral assemblages from other basins of the Tethys, but are comparatively low when compared with diversities exhibited by many Recent and fossil coral communities. The corals studied apparently found optimal ecological conditions for their development on the marly slopes of the western Maestrat Basin. This is primarily expressed in the unusually large dimensions (up to 2.3 m in width) of some of the coral colonies when compared to other Cretaceous occurrences, and in the persistence and resilience of the coral populations. The observed coral genera and species (suborders Archeocaeniina, Faviina, Fungiina and Microsolenina) are very common in the time interval between the Barremian and the Early Albian and most of them have been reported from several other localities in the western and central Tethyan realm. In addition, the coral-bearing levels also contain the poorly known and exotic genera Agrostyliastraea and Procladocora. There are no significant differences at species level or in community structure between the Early and Late Aptian faunas investigated. Therefore, the coral communities as well as the environmental conditions controlling them would have been relatively stable during the time intervals when these corals flourished. An important palaeoecological implication is that comparatively low species diversities and the absence of reef frameworks do not necessarily imply unfavourable environmental conditions for coral growth. Furthermore, this study may serve as an example for the analysis of other level-bottom coral communities displaying a loose growth fabric

Une excursion négative de la courbe isotopique du carbone au sein de la Zone à Dufrenoyia furcata : proposition pour un nouvel épisode permettant la corrélation chimiostratigraphique dans l'Aptien

In this work we discuss a proposed updated division of the C7 isotope segment of Menegatti et al. (1998). The new standard division of the segment C7 is based on a revision of published Barremian-Aptian carbon isotope curves from stratigraphic sections of the Prebetic Domain in Spain. It includes four distinct isotopic subunits labeled C7a to C7d, with a characteristic negative carbon isotope excursion at the base of the segment and which correlates with the Dufrenoyia furcata ammonite Zone. The negative excursion is recognized on a regional extent, and the term Intra-Furcata Negative Excursion (IFNE) is proposed to identify it. We provide possible sites correlatable with the IFNE in both the Old and New worlds, which suggest its potential use as an even global chemostratigraphic marker for the Aptian record.Dans ce travail nous proposons une mise à jour de la subdivision du segment isotopique C7 de Menegatti et al. (1998). Ce nouveau standard est fondé sur une révision des courbes isotopiques du carbone publiées pour le Barrémo-Aptien à partir de coupes stratigraphiques du domaine prébétique en Espagne. Le segment C7 inclut quatre sous-unités isotopiques distinctes répertoriées C7a à C7d et est caractérisé à sa base par une excursion isotopique négative qui est corrélée avec la Zone d'ammonites à Dufrenoyia furcata. Cette excursion négative est reconnue à l'échelon régional, et le terme Excursion Négative Intra-Furcata (ENIF) est proposé pour sa dénomination. Nous proposons d'autres sites, à la fois dans l'Ancien et le Nouveau Monde, qui paraissent révéler cette ENIF, ce qui suggère ses potentialités comme marqueur chimiostratigraphique global pour l'Aptie