Search results for "7(60)"
showing 10 items of 1678 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…
Seismites resulting from high-frequency, high-magnitude earthquakes in Latvia caused by Late Glacial glacio-isostatic uplift
2016
Abstract Geologically extremely rapid changes in altitude by glacial rebound of the Earth crust after retreat of the Scandinavian Ice Sheet at the end of the last Weichselian glaciation influenced the palaeogeography of northern Europe. The uplift of the Earth crust apparently was not gradual, but shock-wise, as the uplift was accompanied by frequent, high-magnitude earthquakes. This can be deduced from strongly deformed layers which are interpreted as seismites. Such seismites have been described from several countries around the Baltic Sea, including Sweden, Germany and Poland. Now similarly deformed layers that must also be interpreted as seismites, have been discovered also in Latvia, a…
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…
Growth patterns, sexual dimorphism, and maturation modeled in Pachypleurosauria from Middle Triassic of central Europe (Diapsida: Sauropterygia)
2018
Bone tissue, microanatomy, and growth are studied in humeri of the pachypleurosaurs Dactylosaurus from the early Anisian of Poland and of aff. Neusticosaurus pusillus from the Lettenkeuper (early Ladinian) of southern Germany. Histology and modeled growth curves are compared to already published data of other pachypleurosaurs. Therefore, we herein established growth curves for Anarosaurus from the middle Anisian of Winterswijk (the Netherlands) and for pachypleurosaurs from the Anisian/Ladinian of the Alpine Triassic (i.e., Neusticosaurus spp. and Serpianosaurus). Humeri of Dactylosaurus, Anarosaurus, and aff. N. pusillus, all from the Germanic Basin, usually display an inner ring of (pre-)…
A Peptidoglycan-Remodeling Enzyme Is Critical for Bacteroid Differentiation in Bradyrhizobium spp. During Legume Symbiosis.
2016
International audience; In response to the presence of compatible rhizobium bacteria, legumes form symbiotic organs called nodules on their roots. These nodules house nitrogen-fixing bacteroids that are a differentiated form of the rhizobium bacteria. In some legumes, the bacteroid differentiation comprises a dramatic cell enlargement, polyploidization, and other morphological changes. Here, we demonstrate that a peptidoglycan-modifying enzyme in Bradyrhizobium strains, a DD-carboxypeptidase that contains a peptidoglycan-binding SPOR domain, is essential for normal bacteroid differentiation in Aeschynomene species. The corresponding mutants formed bacteroids that are malformed and hypertrop…
"Table 1" of "Transverse momentum spectra and nuclear modification factors of charged particles in pp, p-Pb and Pb-Pb collisions at the LHC"
2019
Transverse momentum spectra of charged particles in PbPb collisions in nine centrality classes.
"Table 1" of "$\phi$-meson production at forward rapidity in p-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV and in pp collisions at $\sqrt{s}$ = 2…
2017
$p_{\rm T}$-differential production cross section of $\phi$ in pp at $\sqrt{s_{\rm NN}}$=2.76 TeV, in the rapidity range 2.5 < y < 4
"Table 7" of "Transverse momentum spectra and nuclear modification factors of charged particles in pp, p-Pb and Pb-Pb collisions at the LHC"
2019
Additional systematic error for PBPB 0-5 pct data: +2.2 pct -2.2 pct Additional systematic error for PBPB 5-10 pct data: +2.2 pct -2.2 pct Additional systematic error for PBPB 10-20 pct data: +2.4 pct -2.4 pct Additional systematic error for PBPB 20-30 pct data: +2.7 pct -2.7 pct Additional systematic error for PBPB 30-40 pct data: +3.4 pct -3.4 pct Additional systematic error for PBPB 40-50 pct data: +3.7 pct -3.7 pct Additional systematic error for PBPB 50-60 pct data: +4.9 pct -4.9 pct Additional systematic error for PBPB 60-70 pct data: +6.7 pct -6.7 pct Additional systematic error for PBPB 70-80 pct data: +7.1 pct -7.1 pct.