Search results for " Triassic"

Gli ammonoidi della collezione Gemmellaro. La catalogazione informatizzata come base per la revisione sistematica.

2010

Climatic influence on the growth pattern ofPanthasaurus maleriensisfrom the Late Triassic of India deduced from paleohistology

2020

Metoposaurids are representatives of the extinct amphibian clade Temnospondyli, found on almost every continent exclusively in the Late Triassic deposits. Osteohistologically, it is one of the best-known temnospondyl groups, analyzed with a wide spectrum of methods, such as morphology, morphometry, bone histology or computed modelling. The least known member of Metoposauridae isPanthasaurus maleriensisfrom the Pranhita-Godavari basin in Central India, being geographically the most southern record of this family. For the first time the bone histology of this taxon was studied with a focus on the intraspecific variability of the histological framework and the relationship between the observed…

The revision of Pinacoceras (Ammonoidea, Upper triassic) of the Gemmellaro Collection.

2010

Positive Sulfate Sulfur Isotope Excursion Indicates Large-Scale Pyrite Burial and Marine Anoxia during the End–Triassic Mass Extinction

2020

The late Rhaetian–early Hettangian transition is characterised by the emplacement of Central Atlantic magmatic province and associated climatic effects, coincident with a severe biotic crisis (~201.5 Ma). The oxygen deficiency in the ocean realm is possibly linked to this significant loss in marine biodiversity. However, direct evidence of contemporaneous development of marine anoxia on a global scale has been lacking and the relationship between oxygen and extinction is unclear. Here we report carbonate-associated sulfate δ34S data from three sections across the Late Triassic–Early Jurassic transition. We find synchronous large positive δ34S shifts with a magnitude of >10‰ in the latest…

Multistage geochronological evolution of the Velká Fatra Mountains—a combined TIMS and ion-microprobe study on zircons

2005

Abstract New isotopic and geochronological data from the Velka Fatra Mountains (Tatric Unit of the Central Western Carpathians) are presented and discussed with a focus on the Variscan orogeny and events during Permian and Early Triassic times. The investigated samples are meta- to per-aluminous granitoids and their trace element patterns indicate a volcanic arc origin. This study presents U–Pb single zircon data, measured on TIMS as well as on an ion-microprobe (SIMS). The zircon age determinations were additionally constrained by cathodoluminescence (CL). Most of the investigated granitoids yield Variscan emplacement ages of about 310 Ma. However, for the Lubochna leucogranite a Triassic …

A Triassic carbonate platform edge in the Sciacca zone: implications for the accretion of the Maghrebian chain in southwestern Sicily

2008

Architecture and dynamics of a Maghrebian carbonate platform-basin transition around the Triassic/Jurassic Boundary: Sciacca zone, Sicily.

2007

Synsedimentary-tectonic, soft-sediment deformation and volcanism in the rifted Tethyan margin from the Upper Triassic–Middle Jurassic deep-water carb…

2014

Abstract The Pizzo Lupo section (Sicanian Mts, central Sicily) is an Upper Triassic–Lower Jurassic condensed deep-water succession, where the relationships among synsedimentary tectonic, soft-sediment deformations, volcanism and lithological changes reflect the evolution of a rift-basin. The morphostructural setting of the studied basin appears as a gently dipping slope where a fault-delimited area (graben to halfgraben) was developed. The instability of the sea floor, related to the seismic shocks, was the cause of the gravity-driven deformational sedimentary structures (slumping, breccia channelized bodies). The partly stratified basaltic rocks, with disorganized and chaotic stratificatio…

New insights into the diversity dynamics of Triassic conodonts

2013

International audience; In this paper, we examine the diversity trends and the evolutionary patterns of Triassic conodonts through a newly powered large-scale data-set compiled directly from the primary literature. Paleodiversity dynamics analyses have been undertaken by working at the species level and using a system of time units based on biozone subdivisions for a fine temporal level resolution. The role of heterogeneous duration of taxa in diversity estimates has been evaluated through the probabilistic profiles. Results reveal three different stages in the diversity behaviour of Triassic conodonts from standing metrics delimited by two inflections at the mid-Anisian and mid-Carnian. Su…

Exploring the major depletions of conodont diversity during the Triassic

2014

International audience; In this paper, we show that the Triassic fossil record reflects just two great depletions of conodont diversity before the Rhaetian, which occurred in the Smithian (Olenekian, Early Triassic) and in the Julian (Carnian, Late Triassic). By exploring this context, our results highlighted that they respond to different origination?extinction dynamics. Thus, while the Smithian diversity depletion can be interpreted as a consequence of elevated extinction, the Julian diversity depletion was triggered by fluctuations in origination regime. This evidence suggests that, despite the role of extinction on diversity losses, conodonts suffered crucial changes on the origination …