Search results for "Palaeobiogeography"
showing 10 items of 12 documents
REWORKING OF FUSULINIDS AND CALCIPHAERIDS IN THE LERCARA FORMATION (SICILY, ITALY); GEOLOGICAL IMPLICATIONS
2004
Different fusulinids have been identified in the Lercara Formation (Sicily). They are: Reichelina sp., Schubertella paramelonica, Toriyamaia (?) sp., Neofusulinella lantenoisi, Yangchienia compressa, Rauserella staffi, Darvasites contractus, Chalaroschwagerina (Taiyuanella?) aff. davalensis, Levenella aff. evoluta, Pamirina darvasica, and Neoschwagerina ex gr. craticulifera. Small Permian foraminifers, as well as the calcispherid Asterosphaera pulchra also exist. The microfossils indicate reworking of different Permian stages, at different periods of time, and possibly also of the Mississippian (Early Carboniferous). All these resediments have been deposited within the Lercara Formation, a …
Pseudoskirroceras, a remarkable but poorly known Early Pliensbachian Tethyan ammonite genus: New data from the High Atlas (Morocco).
2007
13 pages; International audience; The discovery of new Early Pliensbachian ammonite faunas in Central High Atlas (Morocco) allows the re-examination of the taxonomic, stratigraphical and palaeogeographical framework of the genus Pseudoskirroceras, an intriguing but until now poorly known Tethyan taxon. For the first time, several specimens of Pseudoskirroceras mastodon (Fucini, 1935) the type species of the genus, have been collected in a well-known stratigraphical context. This material allows the evaluation of intra-specific variability and consequently the assessment of the taxonomical relevance of various geometrical and ornamental features. The best diagnostic features are the clearly …
The Gemmellaro Collection: first record of an anomuran from the Tithonian of Sicily, Italy
2017
A recent field trip to Sicily and an examination of decapod crustacean collections at the Museo Geologico G.G. Gemmellaro in the centre of Palermo, Sicily (Italy), has demonstrated that most of the anomuran and brachyuran material described by Gemmellaro (Gemmellaro GG. 1869. Studi paleontologici sulla fauna del Calcare àTerebratula janitordel nord di Sicilia. Palermo: Lao, vol. 1, pp. 11–18) from the Tithonian of that island is still present. Interestingly, a single specimen in this lot was never mentioned, described or illustrated by that author. The species to which this particular individual is here shown to belong,Gastrosacus tuberosus, was first described and named 26 years later, in …
Gastropods from upper Pliensbachian–Toarcian (Lower Jurassic) sediments of Causses Basin, southern France and their recovery after the early Toarcian…
2015
AbstractA gastropod fauna has been studied from upper Pliensbachian – upper Toarcian deposits of two sections of the Causses Basin (southern France) in order to investigate the mode of recovery after the early Toarcian anoxic event. The fauna consists of 15 species, one of which is new (Bathrotomaria kronzwilmesorumsp. nov.). Their stratigraphical distribution shows two peaks of diversity – in the Bifrons Zone (Bifrons Subzone) and in the Aalensis Zone (Mactra Subzone) – which reflect brief times during which the oxygen content and bottom consistency favoured the settlement of a relatively diversified fauna. In the Variabilis–Pseudoradiosa zones, gastropods are only represented by two speci…
Pseudolillia Maubeuge, 1949 (Ammonitida, Hildoceratidae) in the Lower Jurassic (Toarcian) of the NE Spain
2017
In the present paper, 147 specimens assigned to the genus Pseudolillia Maubeuge, 1949 are studied. This is a considerably high number of samples in comparison with those known in other geographical areas where they have been cited, such as northern France, the Pyrenees, the Betic Range, Morocco, Portugal, Italy, Hungary and Bulgaria. The six taxa described, P. murvillensis, P. hispanica, P. emiliana, P. donovani, Pseudolillia ? n. sp. (en García-Gómez & Rivas, 1980), and Pseudolillia ? sp., come from 22 sites in the Cantabrian and Iberian Ranges and the Isle of Majorca. Their presence in expanded sections enabled us to situate the stratigraphic position of the genus between the upper part o…
The Sinemurian and Pliensbachian ammonites of the «Calcaires de Laffrey » (Isère, France). Description of a new taxon Pseudojamesonites nov. gen. mou…
2009
Some ammonites, formerly collected by René Mouterde within the Sinemurian and Pliensbachian beds of the “Calcaires de Laffrey” (Isère, France), are first described and illustrated in this work. The Sinemurian (Semicostatum chronozone) assemblage, chiefly constituted by Arnioceras gr. robustum (Quenstedt, 1884), is rather usual for the NW European faunas. Conversely, the Pliensbachian (Jamesoni chronozone, Brevispina subchronozone) assemblage is very peculiar. It is chiefly constituted by a very rare species Pseudojamesonites nov. gen. mouterdei nov. sp. (Eoderoceratoidea) which is here described for the first time. The presence, in significant proportion, of this new taxa in the Early Plien…
Hettangian ammonites from the old iron mine of Beauregard (Thoste, Côte-d’Or, France).
2012
The ammonite fauna of the old iron mine of Beauregard is reviewed. Only nine specimens from this locality are presently known. They are housed in the collections of the “Musée de Semur-en-Auxois”, of the “Muséum national d’Histoire naturelle” (Paris) and of the “Ecole Nationale Supérieuredes Mines” (Claude Bernard University, Lyon 1). The age, or possibly the ages, of these ammonites remain to precise in a coarsely defined time-span including the upper part of the early Hettangian and the middle Hettangian (pro parte?). These fossils, usually finely preserved, were collected during the nineteenth century thanks to intensive mining in the Thoste-Beauregard area. They are illustrated uniforml…
The Sinemurian ammonites of the Lusitanian Basin (Portugal): an example of complex endemic evolution.
2010
29 pages; International audience; This 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 (Su…
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…
Early Palaeozoic palaeobiogeography and palaeoecology of stylophoran echinoderms
2007
44 pages; International audience; Stylophorans (cornutes, mitrates) represent one of the most diverse classes of Cambro-Ordovician echinoderms. They were freeliving, benthic, non-radiate forms, closely related to asterozoans and crinoids. Taphonomic, sedimentological, and palaeosynecological data provide useful information on key aspects of stylophoran palaeoecology. Such a combined approach suggests that the rarity of stylophorans in proximal environments (above storm-wave base) was probably original and does not exclusively result from the possession of a loosely articulated polyplated calcitic test. Conversely, stylophorans were relatively abundant in deeper settings (below storm-wave ba…