Search results for "lcsh:QE701-760"
showing 10 items of 16 documents
Stage boundaries, global stratigraphy, and the time scale: towards a simplification
2004
International audience; This paper examines four facets of stratigraphic terminology and usage considered faulty and proposes corrective measures. The four perfectible areas are: (1) The system of dual nomenclature requiring discrete terminologies for the superpositional and temporal aspects of rock units. (2) The premise that a GSSP establishes the base of a stage as being coincident with the top of the preceding stage rather than simply defining it as the boundary between stages. (3) The rejection of supplementary (auxiliary) sections that would broaden the knowledge of a GSSP and enlarge the area in which it is easily usable. (4) The current dual system of nomenclature for Precambrian an…
Problems in the identity of "Crioceras" barremense Kilian, 1895 (Ancyloceratida, Late Barremian), and their proposed resolution
2010
17 pages; The study of "Crioceras" barremense KILIAN was undertaken as a part of the revision of the Hemihoplitidae. This species was considered "classic" and has been used as the index of an Upper Barremian subzone; this usage raises a number of problems. The type specimen from Tyrol was a fragment described and illustrated by UHLIG as Crioceras sp. ind. aff. roemeri. This specimen could not be retrieved, and a topotype could not be collected. Our study revealed that there is both a biostratigraphic hiatus and important differences between conceptions of this species: (1) that ascribed UHLIG's type specimen (Upper Barremian, Tyrol), (2) KILIAN's concept of the specimen he found and named "…
Pseudoshasticrioceras bersaci nov. sp. (Ammonoidea, Gassendiceratinae), and new ammonite biohorizon for the Upper Barremian of southeastern France
2009
International audience; Research in the Feraudianus Subzone of the Sartousiana Zone of the Barremian stage led to the discovery of a new species of Pseudoshasticrioceras: P. bersaci nov. sp. Its study provides evidence concerning the developments of the latest Gassendiceratinae BERT et alii, 2006, and the relationship between the genus Pseudoshasticrioceras DELANOY, 1998, and Gassendiceras BERT et alii, 2006. In particular, this new species is derived from Pseudoshasticrioceras magnini (DELANOY, 1992) by a minor revision in the processes of ontogenesis (retardation of ornamentation - neoteny). However, the evolution towards Pseudoshasticrioceras autrani DELANOY, 1998, implies a "failure" in…
Globacrochordiceras gen. nov. (Acrochordiceratidae, late Early Triassic) and its significance for stress-induced evolutionary jumps in ammonoid linea…
2013
<i>Globacrochordiceras transpacificum</i> gen. et sp. nov. is an ammonoid (Ammonoidea, Cephalopoda) with a shell characterized by plicate ribbing (rounded and undulating ribs strengthening on the venter without interruption), increasing involution through ontogeny, overhanging and deep umbilical wall, absence of tuberculation, subtriangular whorl section, globose adult shape with a closed umbilicus followed by an abrupt egressive coiling, and a subammonitic adult suture line. This new taxon occurs in Nevada (USA) and in Guangxi (South China). It has its typical occurrence within the <i>Neopopanoceras haugi</i> Zone of late Spathian age (Early Triassic). The plicate r…
Comment on “An early Late Triassic long-necked reptile with a bony pectoral shield and gracile appendages” by Jerzy Dzik and Tomasz Sulej
2017
Comment on “An early Late Triassic long-necked reptile with a bony pectoral shield and gracile appendages” by Jerzy Dzik and Tomasz Sulej
Influences boréales dans le bassin de Mons (Belgique) à l'Albien
2007
International audience; The occurrence of marine dinoflagellates (including Cauca parva from the Boreal Province), acritarchs and the organic lining of foraminifers suggest Boreal marine influences in the Wealden facies of the Mons basin (Belgium) during the Late Albian.
Late Carnian-Early Norian ammonoids from the GSSP candidate section Pizzo Mondello (Sicani mountain, Sicily).
2012
A small collection of ammonoids from the Upper Triassic Scillato Formation at Pizzo Mondello (Agrigento, Sicily) is studied. The specimens were collected in a framework of a project aimed at providing an integrated high-resolution bio-chronostratigraphic support to the Upper Carnian-Norian magnetostratigraphic scale defined at this site, that is located in an historical area from which G.G. Gemmellaro collected the Upper Triassic of ammonoids monographed at the beginning of the XX century. The specimens from Pizzo Mondello were bed-by-bed sampled and represent the first collection of Upper Triassic ammonoids described from Sicily since Gemmellaro time. Quite several levels of the Pizzo Mond…
Early Jurassic (Sinemurian to basal Toarcian) ammonites of the Brescian Prealps (Southern Alps, Italy).
2017
This work provides a more precise up-to-date biostratigraphical framework of the Early Jurassic ammonite succession of the Brescian Prealps with more than seventy taxa for the Sinemurian, Pliensbachian and basal Toarcian corresponding to a about 30 horizons or faunal assemblages rather well correlable with the NW European standard zonation. These results are supported with already published data, new data from recent field investigations, revised contributions of different authors and with the study of the historical collection of the Museum of Natural Sciences of Brescia (Northern Italy). The biohorizons are referred to the Lower Jurassic carbonate series of the Brescian Prealps, cropping …
THE GARGANO TERRE ROSSE INSULAR FAUNAS: AN OVERVIEW
2010
After forty years from its discovery, the history of the field surveys and of the researches on the fossiliferous deposits on Gargano is briefly reported. The Gargano fauna belongs to the Abruzzo-Apulian Palaeobioprovince (including also Scontrone and Palena, Abruzzo). The fossil assemblage comprehends all the classes of terrestrial vertebrates: Reptilia, Amphibia, Aves and Mammalia. The faunal composition is unbalanced and presents the features of a typical insular endemic fauna. The bulk of the assemblage is composed of small mammals and birds. Based on literature, we report the most characteristic features, phylogenetic relationships, and evolutionary remarks on a list of mammals, focusi…
Zonation by ammonites and foraminifers of the Vraconnian-Turonian interval: A comparison of the Boreal and Tethyan domains (NW Europe / Central Tunis…
2008
International audience; Since the end of the 19th century the interval comprising the uppermost Upper Albian, the Cenomamian, the Turonian and the basal Coniacian has been subdivided, first into ammonite zones, then, beginning in the middle of the 20th century, into zones of planktonic foraminifera. These two groups, one macrofossil, the other microfossil, are particularly effective for bio-chronostratigraphy thanks to their rapid rates of evolution. But differences in the faunal makeup between the Boreal domain (northwestern Europe) and the Tethyan domain (Mediterranean) have for a long time hindered precise correlation of the two domains. Today, in a time interval covering about 16 millio…