Biostratigraphie et paléoécologie des peuplements d'ostracodes dans le Domérien du Bassin Lusitanien, Portugal

The Domerian sections from the Lusitanian Basin of São Pedro de Muel, Rabaçal and Tomar have provided us with more than 1100 Ostracods belonging from 18 genus and about 48 species. The faunal diversity and density of the associations decrease in space (from Tomar to Rabaçal and São Pedro de Muel) and time, with favourable environments for the proliferation of Ostracods at the lower part of the sections (Stokesi subzone) and more hostile at the upper part (Ragazzonii subzone). The Monestieri and Nitescens horizons and the Subnodosus subzone are characterized by a typical assemblage of Ostracods. The palaeoecological Ostracod indexes reveal the fluctuations of the oxygenation, temperature, depth and hydrodynamism of the water, on the different sections and on the whole platform. They display a diachronous cooling in the Lower Domerian series. In the upper part of the Middle and in the Upper Domerian, the deeper, less oxygenated and cooler waters prevent the development of the Ostracod faunas

The Pliensbachian ammonites of the Algarve Basin (Portugal) and their palaeobiogeographical significance for the ''Iberia-Newfoundland'' conjugate margins.

16 pagesInternational audienceA review of the Pliensbachian ammonite faunas of the Algarve Basin is given covering their taxonomy, stratigraphy and palaeobiogeography (palaeobiodiversity). This review is based on both an extensive revision of the previously collected and/or published material and on new finds precisely located within the ammonite succession. This new material allows us to clarify the variations within the most abundant species--a new species Reynesocoeloceras elmii nov. sp. is described--and to improve our understanding (palaeobiodiversity, palaeobiogeography and bio- or chrono-stratigraphy) of the two single known Pliensbachian fossiliferous assemblages in the Algarve Basin. The first of these assemblages is relatively diverse and is ascribed to the upper half of the Luridum Subchronozone. The second assemblage is less diversified and probably partly condensed. It is broadly attributed to the upper half of the Stokesi Subchronozone. Despite the newly collected ammonites and extensive prospecting, our knowledge of the Pliensbachian ammonite faunas of the Algarve remains fragmentary. Therefore, it is difficult to propose an incontrovertible extensive palaeobiogeographical interpretation for these faunas, but it seems that Tethyan (Mediterranean) affinities were of major importance whereas there were probably no NW European influences via the Lusitanian Basin

The Sinemurian ammonites of the Lusitanian Basin (Portugal): an example of complex endemic evolution.

29 pagesInternational audienceThis work synthesizes all of the observations since the late nineteenth century of the highly endemic Late Sinemurian (Obtusum Chronozone) ammonite faunas of the Lusitanian Basin. It is based mainly on recent abundant collections from the Penedo da Saudade section near São Pedro de Muel (Leiria, Portugal). This rich material (some eight species and four genera), collected bed by bed, allows us to propose an initial biostratigraphic, palaeobiogeographic, evolutionary and taxonomic synthesis of these mostly endemic faunas. The genus Epophioceroides n. gen. is new and three new species are identifi ed: Epophioceroides apertus n. gen. n. sp., Ptycharietites (Subgen. indet. A) asteroceroides n. sp. and Ptycharietites (Ptycharietites) heterogenus n. sp. So far they have been found at São Pedro de Muel only. The only non-endemic ammonite, Asteroceras sp. indet., collected from the base of the fossiliferous sequence, suggests an age in the Obtusum Chronozone for the subsequent taxa. Most probably faunas belong to the Stellare Subchronozone but taxa from the highest fossiliferous levels may also belong to the Denotatus Subchronozone. The newly collected material requires the morphological range of the genus Ptycharietites to be extended to include late forms that become either clearly evolute (subserpenticone) such as Ptycharietites (Pompeckioceras) cf. onchocephalus or clearly involute (suboxycone) such as Ptycharietites (? Subgen. indet. B) sp. indet. A. In terms of ontogeny, paedomorphosis – a rare “size-based” heterochronic process among the Asteroceratinae subfamily – is shown to be of major importance throughout the evolution of the genus Ptycharietites. In palaeobiogeographic terms all endemic Late Sinemurian (Obtusum Chronozone) ammonite faunas (Ptycharietites and Epophioceroides n. gen.) of the Lusitanian Basin remain poorly understood. While they suggest marked isolation of the Lusitanian Basin and perhaps also constraining environmental conditions during the Obtusum Chronozone, there is nothing to indicate whether other basins of the “Iberia-Newfoundland” conjugate margins experienced the same endemic trend. Nor is it clear whether the Late Sinemurian endemic faunas are closely related to NW European or to W Tethyan (Mediterranean) faunas. However, the earliest ammonite collected from the São Pedro de Muel section (i. e., Asteroceras sp. indet., bed 500b) suggests a possible NW European affi nity

Ammonites from the Apoderoceras beds (Early Pliensbachian) in São Pedro de Muel (Lusitanian Basin, Portugal).

24 pagesInternational audienceThe lowermost Portuguese Pliensbachian is characterized by the association of Apoderoceras dunrobinense Spath, Tragophylloceras numismale (Quenstedt) and Vicininodiceras aff. mouterdei Donovan. This ammonite fauna indicates the lower part of the Jamesoni Chronozone (lower to middle Taylori Subchronozone). Thanks to the numerous specimens collected, the ontogeny and variability of A. dunrobinense Spath, could also be investigated. The paleogeographical distribution of these ammonites underlines the close connections between the Lusitanian Basin and the Euroboreal seas during the Early Pliensbachian

Atlas des fossiles caractéristiques du Lias portugais III a) Domérien (Ammonites).

45 pagesInternational audienceCe fascicule est le troisième de l'Atlas des fossiles caractéristiques du Lias portugais; il fait suite au fascicule I consacré aux faunes du Lias Inférieur (Hettangien-Sinémurien) et au fascicule II dédié aux faunes de la première partie du Lias Moyen (Carixien). Le fascicule III est consacré à la deuxième partie du Lias Moyen, le sous-étage Domérien. Contrairement aux publications précédentes, le présent travail se restreint aux seules ammonites. Une cinquantaine d'espèces sont brièvement décrites et figurées. Les autres taxons (nautiles, bélemnites, brachiopodes, lamellibranches...) feront l'objet d'un prochain fascicule. Le but de l'Atlas des fossiles caractéristiques du Portugal vise à faire connaître à tous ceux qui s'intéressent à la géologie du Portugal, les principales faunes liasiques. Il est notamment conçu pour fournir un support largement illustré pour les études de terrain. Cette compilation offre une image représentative des macrofaunes d'invertébrés portugais et dans le cas des faunes d'ammonites, elle est même exhaustive et peut être utilisée par les spécialistes notamment dans les domaines de la biostratigraphie et de la paléobiogéographie

Carcinoma epidermóide "in situ" em divertículo de Zenker

The epidermoid carcinoma "in situ" in a Zenker's diverticulum is a rare disease. The goal of this work is to report one case of epidermoid carcinoma "in situ" in a Zenker's diverticulum of long lasting symptomatology, treated by conservative surgery. In ambulatorial attendance, this patient showed a good evolution and favorable prognosis