Search results for "lcsh:Paleontology"
showing 6 items of 16 documents
Middle Triassic (Ladinian) deep-water sediments in Sicily: New findings from the Madonie Mountains
2012
A section of carbonate megabreccias grading upward to deep-water Daonella limestones is described from the locality of Sant’Otiero, near Petralia Sottana, in the Madonie Mountains (Sicily). The megabreccia mainly consists of neritic elements containing dasycladalean algae (Diplopora annulatissima Pia) along with benthic foraminifers and problematics. The overlying calcilutitic strata are characterized by lumachella intercalations containing the bivalve Daonella tyrolensis Mojsisovics suggesting an early Late Ladinian (Protrachyceras longobardicum ammonoid zone) age. We informally name the Daonella limestone as the calcare di Sant’Otiero (Sant’Otiero limestone). The Daonella limestones along…
Support for a Vraconnian Stage between the Albian sensu stricto and the Cenomanian (Cretaceous System)
2008
The geological scale for the middle Cretaceous currently used throughout the world was proposed by Alcide d'Orbigny in the XIXth century between the years 1842 and 1847 and establishes the succession of stages as Albian, Cenomanian and Turonian. In 1868 Renevier proposed that a supplemental chronostratigraphic division be intercalated between the Albian and the Cenomanian: the Vraconnian stage. This term was not generally accepted and after a period when it was referred to by Breistroffer (1936) as a substage constituting the upper part of the Albian, as an equivalent of the Stoliczkaia dispar ammonite Zone, its abandonment was "recommended" by the Conference on the Lower Cretaceous held in…
Zones d'ammonites et de foraminifères du Vraconnien au Turonien : Une comparasion entre les domaines boréal et téthysien (NW Europe / Tunisie central…
2008
International audience; Depuis la fin du 19ème siècle, l'intervalle comprenant l'Albien supérieur élevé, le Cénomanien, le Turonien et le Coniacien basal a été subdivisé d'abord en zones d'ammonites puis, à partir du milieu du 20ème siècle, en zones de foraminifères planctoniques, deux groupes de macro- et de microfossiles particulièrement efficaces en bio-chronostratigraphie grâce à leur taux d'évolution rapide. Toutefois, des différences de compositions fauniques entre le domaine boréal (Europe du Nord-Ouest) et le domaine téthysien (Méditerranée) ont longtemps empêché des corrélations précises entre ces deux domaines. Aujourd'hui, dans un intervalle de temps couvrant environ 16 millions …
New skulls of the basal sauropodomorph Plateosaurus trossingensis from Frick, Switzerland: is there more than one species?
2021
The Triassic basal sauropodomorph Plateosaurus trossingensis is well-known from mass accumulations at the German localities of Trossingen and Halberstadt and the Swiss locality of Frick, and is significant especially regarding its ta-phonomy and proposed developmental plasticity. These implications, however, rely on the assumption that this material derives from a single species, which has been questioned. Here we describe new skull material from Frick including eight complete and six partial skulls, more than doubling the number of known skulls of P. trossingensis. This exceptional sample size allows for gaining a deeper understanding of variability that may occur in a single species. The …
Calcareous nannofossil events in the Lower-Mildle Pleistocene transition at the Montalbano Jonico section and ODP site 964: Calibration with isotope …
2004
We present quantitative data on calcareous nannofossil biostratigraphy in the section of Montalbano Jonico (Southern Italy). This is one of the candidate Global Statotype Section and Point (GSSP) of the Middle Pleistocene. The first common occurrence (FCO) and last common occurrence (LCO) of Reticulofenestra asanoi are well detectable in the section and are here proposed as additional events for improving biostratigraphic resolution in the interval corresponding to the transition between the small Gephyrocapsa Zone and Pseudoemiliania lacunosa Zone. The potential value of the bioevents is tested in a Mediterranean deep-sea core of ODP Site 964, located in the Ionian Sea. At Site 964 the FCO…
Calcareous Nannofossil Biostratigraphy and Chronostratigraphy of ODP Hole 964D (eastern Mediterranean Sea)
2008
Quantitative analyses of calcareous nannofossil were carried out on sediments from ODP Hole 964D succession, recovered in the Ionian Sea, Eastern Mediterranean. Results show that the sedimentary sequence, spanning from about 3.5 Ma (Early Pliocene) to the Present, has been investigated through an average sampling resolution of less than 30 kyr. The detailed subdivision into 11 biozones makes it possible to recognize chronostratigraphic the boundaries in the Early Pliocene-Middle Pleistocene interval. Finally, two sedimentary gaps, lasting at least 340 kyr and 120 kyr respectively, have been recognized between the Zanclean and Piacenzian and in the lower part of the Early Pleistocene. SHORT …