34 research outputs found
Inflation du nombre de genres monospécifiques chez les brachiopodes : progrès ou régression ? Une approche prosaïque d'un problème réel
Depuis le XIXe siècle, environ 1800 genres ou sous-genres de brachiopodes ont été créés pour la période couvrant le Silurien et le Dévonien. On constate, depuis quelques années, une inflation considérable du nombre de genres n'incluant qu'une seule et unique espèce. Sans remettre en cause les progrès technologiques, on peut cependant s'interroger sur la pertinence de la méthodologie adoptée par nombre d'auteurs et sur l'utilité in fine des genres monospécifiques, tant sur le plan de la systématique que sur celui des disciplines annexes. Certaines politiques éditoriales ou encore l'évaluation des appels à projets ne sont peut-être pas étran-gères à ce constat et mériteraient d'être revues.Since the 19th century, about 1800 brachiopod genera or subgenera have been erected for the period covering the Silurian to the Devonian. In recent years, there has been a pronounced increa-se in the number of genera containing a single species. Without questioning the technological advan-ces, one can, however, question the value and usefulness of monospecific genera both for systematics and palaeogeographical studies. Some editorial policy regarding erection of new monospecific genera and/or the evaluation of calls for projects are now needed
New data on Angustiphyllum Altevogt 1965, an automobile free-living rugose coral from the Eifelian of the Western Armorican Massif (France)
accessible à l'adresse suivante : http://popups.ulg.ac.be/Geol/document.php?id=3761International audienceThe genus Angustiphyllum is recorded for the first time in the Armorican Massif (Rade de Brest) and two new species are erected: A. stylophorum and A. vidalae. The well preserved material shows the indisputable presence of costae on the exterior side of the corallum, which, besides the wedge-like morphology of the corallum, constitutes the main diagnostic feature of the genus. Angustiphyllum seems to be a good index for the Upper Eifelian of the Ibero-Armorican Domain
Lower Devonian faunas and palynomorphs from the Dornes Syncline (Central Iberian Zone, Portugal): stratigraphical and paleogeographical implications
International audiencen the Dornes syncline, southern Central Iberian Zone, Portugal, the uppermost levels of the Serra do Luação Formation up to now have been considered to be of Pridoli-Lochkovian? age because they lie immediately under the Dornes Formation, which is of Pragian age and is well defined stratigraphically. New paleontological elements including benthic faunas and palynomorphs allow us to confirm that the top of the Serra do Luação Formation is securely Lochkovian, for upper Lochkovian strata are present although relatively thin. The transition from the Serra do Luação to the Dornes formations and their lithostratigraphical relationship are now clear: the terrigenous succession belongs to the Serra do Luação Formation and the limestones represent the Dornes Formation. The benthic faunas clearly have North-Gondwanan affinities
Lower Devonian faunas and palynomorphs from the Dornes Syncline, Central Iberiam Zone, Portugal : stratigraphical and paleogeographical implications
In the Dornes syncline, southern Central Iberian Zone, Portugal, the uppermost levels of the Serra do Luação Formation up to now
have been considered to be of Pridoli-Lochkovian? age because they lie immediately under the Dornes Formation, which is of
Pragian age and is well defined stratigraphically. New paleontological elements including benthic faunas and palynomorphs allow us
to confirm that the top of the Serra do Luação Formation is securely Lochkovian, for upper Lochkovian strata are present although
relatively thin. The transition from the Serra do Luação to the Dornes formations and their lithostratigraphical relationship are now
clear: the terrigenous succession belongs in the Serra do Luação Formation and the limestones represent the Dornes Formation.
The benthic faunas clearly have North-Gondwanan affinities
A reassessment of the Lochkovian, Lower Devonian, benthic faunas and palynomorphs from the Dornes region, southern Central Iberian Zone, Portugal
A revision of benthic faunas and palynomorphs previously described from the Dornes syncline, southern Central Iberian Zone,
Portugal, complemented with recent research, shows that the Serra de Luação Formation is of Lochkovian age. The systematics of
the benthic faunas, with clear Gondwana affinities, are described in detail
Les faunes et les palynomorphes du Dévonien inférieur du Synclinal de Dornes (Zone Centre-Ibérique, Portugal) : signification stratigraphique et paléogéographique
Dans le Synclinal de Dornes, sud de la Zone Centre-Ibérique, Portugal, le sommet de la Formation de Serra do Luação, était jusqu'à présent attribué au Pridoli-Lochkovien? par sa position relative sous la Forma-tion de Dornes, mieux calée stratigraphiquement et d'âge Praguien. De nouveaux arguments paléonto-logiques concernant les faunes benthiques et les palynomorphes viennent confirmer que le sommet de la Formation de Serra do Luação appartient bien au Lochkovien, les derniers mètres représentant un Lochkovien supérieur fortement condensé. La transition entre les formations de Serra do Luação et de Dornes ainsi que leur position lithostratigraphique sont désormais éclaircies : les alternances silico-clastiques appartiennent bien à la Formation de Serra do Luação tandis que les niveaux calcaires appartiennent à la Formation de Dornès. Les faunes benthiques récoltées indiquent d'évidentes affinités Nord-Gondwaniennes.In the Dornes syncline, southern Central Iberian Zone, Portugal, the uppermost levels of the Serra do Luação Formation up to now have been considered to be of Pridoli-Lochkovian? age because they lie immediately under the Dornes Formation, which is of Pragian age and is well defined stratigra-phically. New paleontological elements including benthic faunas and palynomorphs allow us to confirm that the top of the Serra do Luação Formation is securely Lochkovian, for upper Lochkovian strata are present although relatively thin. The transition from the Serra do Luação to the Dornes formations and their lithostratigraphical relationship are now clear: the terrigenous succession belongs to the Serra do Luação Formation and the limestones represent the Dornes Formation. The benthic faunas clearly have North-Gondwanan affinities
Le passage Ordovicien–Silurien et la partie inférieure du Silurien (Sud-Est du Massif armoricain, France)
Meristella renaudae n. sp., nouveau Meristelliné (Athyridina, Brachiopoda) du gédinnien inférieur du massif armoricain
National audienc
Meristella renaudae n. sp., nouveau Meristelliné (Athyridina, Brachiopoda) du gédinnien inférieur du massif armoricain
National audienc
New record of a Middle Devonian brachiopod fauna from the Northern Arabian Plate, Zap Anticline, Cukurca-Hakkari, Southeastern Turkey
International audienceBrachiopods recently collected from the Zap River Valley area (SE Turkey) allow to establish a Middle Devonian (upper Givetian) age for the upper middle part of the Yiginli Formation which was until now considered as Famennian on the basis of its micropaleontological contents and of its relative position in the series