Search results for "Ammonoidea"
showing 9 items of 29 documents
The recovery and radiation of Early Jurassic ammonoids: morphologic versus palaeobiogeographical patterns
2001
Abstract The recovery and radiation of the Early Jurassic ammonoid morphospace, as represented by nine morphologic groups identified in an earlier study, are traced through the first 36 subzones of the Hettangian to Domerian time interval. A quantitative survey of the dispersion of 436 species over 15 palaeogeographical areas reveals seven palaeobiogeographical patterns, each corresponding to an exclusive set of species exhibiting similar characteristics in terms of distribution and abundance. This study combines morphologic, chronostratigraphical, and palaeobiogeographical data in an attempt to investigate possible connections between morphologic recovery and radiation patterns and the his…
Callovian to lower Kimmeridgian ammonite successions from West Sicily (Roccapalumba) and Northeast Iberian Range (Ariño, Teruel): A key for palaeogeo…
2010
La comparacion de las sucesiones de ammonites en el intervalo comprendido entre el Calloviense y el Kimmeridgiense inferior en la region de Sicilia occidental (Roccapalumba-Sciacca) y la Cordillera Iberica nororiental (Sierra de Arcos) muestra una clara similitud y paralelismo en el desarrollo estratigrafico. Esto incluye el registro incompleto del Calloviense inferior, una amplia laguna estratigrafica (Calloviense inferior-Oxfordiense medio) y un registro mas completo del Oxfordiense medio-superior (biozonas Transversarium-Bifurcatus) y Kimmeridgiense inferior. Esto permite inferir una evolucion paleogeografica paralela en ambas regiones del Tethys. Las asociaciones registradas de ammonite…
Early–middle Jurassic lytoceratid ammonites with constrictions from Morocco: palaeobiogeographical and evolutionary implications.
2008
13 pages; International audience; The ammonite genus Alocolytoceras Hyatt, 1900 is an uncommon lytoceratid with distinctive shell ornament. A set of 58 specimens, recently collected at Amellago in the central High Atlas (Morocco), has enabled us to trace a succession of three species over eight biozones from the Toarcian to the Aalenian. Two specimens from the Lusitanian Basin are added for comparison. Following a review of the genus, based on original specimens and data from the literature, seven species are considered valid. A palaeobiogeographical synthesis of 13 regions demonstrates irregular distribution patterns over time, with a constant presence in the south-west Tethys and an insta…
Les ammonites de l'Hettangien, du Sinémurien et du Pliensbachien inférieur de la Dorsale de Grande Kabylie (Algérie).
2008
Dommergues, Jean-Louis, Cattaneo, Gérard, Aïte, Ramdane, Gélard, Jean-Pierre (2008): Les ammonites de l'Hettangien, du Sinémurien et du Pliensbachien inférieur de la Dorsale de Grande Kabylie (Algérie). Geodiversitas 30 (3): 539-576, DOI: http://doi.org/10.5281/zenodo.5378393
The revision of Pinacoceras (Ammonoidea, Upper triassic) of the Gemmellaro Collection.
2010
Coupures morphologiques et biochronologie chez les Kosmoceratinae de l'Est de la France (Callovien inférieur pp. à Callovien supérieur pp.)
1998
Abstract For the first time in eastern France, a detailed succession of the uppermost Lower Callovian to Lower Upper Callovian Kosmoceratinae is presented, according to the fossils collected in situ at Blye (Jura, France). It is compared with the abundant data from Champagne and Bourgogne. These ammonites may allow more accurate correlations between the subboreal and subtethysian biostratigraphical frameworks. They record numerous morphological changes, sometimes different from those generally accepted. They allow the precise recognition of the limits of the biostratigraphical units, and the definition of successive faunal units available in the lowermost Upper Callovian.
Le dimorphisme chez Perisphinctes (Properisphinctes) cf. bernensis de Loriol (Oxfordien inférieur, région de Cracovie, Pologne)
2004
Resume Une population d'ammonites rapportee a Perisphinctes (Properisphinctes) cf. bernensis de Loriol 1898, d'âge Oxfordien inferieur (zone a Mariae), a ete trouvee dans la region de Cracovie, dans le Sud de la Pologne. L'etude de ces formes a permis de montrer l'existence, au sein de cette espece, d'un dimorphisme microconque/macroconque, qui etait soupconne, mais non encore demontre avec certitude. Cette espece, connue en Europe uniquement par des individus incomplets, precise notre connaissance des perisphinctides de la base de l'Oxfordien inferieur. Pour citer cet article : R. Tarkowski, D. Marchand, C. R. Palevol 3 (2004).
Oxyarietites boletzkyi n. gen., n. sp., nouveau genre et nouvelle espèce d'ammonite dans le Sinémurien inférieur de Bourgogne (France) : un rare préc…
2012
13 pages; International audience; L'une des toutes premières ammonites à coquille presque oxycône observée dans les séries fossilifères après la crise faunique de la limite Trias/Jurassique est décrite. Elle provient du Sinémurien inférieur (chronozone à Semicostatum ou à Turneri) de Bourgogne (Mavilly-Mandelot, Côte-d'Or, France). Cette nouvelle forme, Oxyarietites boletzkyi n. gen., n. sp., possède une coquille involute, comprimée et carénée dont le type clairement suboxycône est nouveau pour le Sinémurien inférieur. En raison de son aire ventrale carénée, ce taxon se rattache probablement à la super-famille des Arietitoidea Hyatt, 1875 sensu Guex (1995) mais son attribution familiale est…
The late Late Albian (Mortoniceras fallax Zone) cephalopod fauna from the Bracquegnies formation at Strépy-Thieu (Hainaut, southern Belgium).
2016
Excavations in 1989-1990 for the construction of a boat lift near the villages of Strépy and Thieu, east of Mons (province of Hainaut, southern Belgium), exposed a 40-metre section of the Bracquegnies Formation (Haine Green Sandstone Group; the ‘Meule de Bracquegnies’ of previous authors). Several hundred well-preserved, silicified cephalopods were collected from between 15 and 35 metres above the base of the sequence temporarily exposed there. The fauna is: Eutrephoceras clementianum (d’Orbigny, 1840), Puzosia (Puzosia) mayoriana (d’Orbigny, 1841), Callihoplites tetragonus (Seeley, 1865), Discohoplites valbonnensis valbonnensis (Hébert & Munier-Chalmas, 1875), Cantabrigites cantabrigense S…