Search results for "Permian"
showing 10 items of 89 documents
Ein neues captorhinomorphes reptil aus dem thüringischen rotliegend (Unter-Perm; Ost-Deutschland)
1991
Thuringothyris mahlendorffae n.gen. n.sp. is described on the basis of the skull roof, palate, stapes and much of the postcranial skeleton from the Upper Rotliegend (Tambach-Schichten) of the Thuringian Forest in eastern Germany. The new taxon shows both protorothyridid and some captorhinid features. The interrelationships of the »Protorothyrididae«, primitive Captorhinidae, and earliest Diapsida are reviewd. The tetrapod material is used to reassess the biostratigraphic position of the fossil-bearing horizon.
Permian of South Europe and its interregional correlation
2000
This contribution is a synthesis of knowledge about the Permian of South Europe, which mainly consists of continental, terrigenous and igneous deposits. Marine sediments crop out in a few Italian areas (eastern Southern Alps, central-southern sectors of the peninsula and Sicily), as well as spread from the ex-Yugoslavia to the present Mediterranean sea, where they represent the westermost patterns of the old Tethys. In this context, data and interpretations vary sensibly from one region to another. Despite this, we have tried to establish the most typical events or features. Although the correlation and nature of some are still in doubt, the effort of reconstructing them is significant. Val…
Two new species of the genusBatropetes(Tetrapoda, Lepospondyli) from the Central European Rotliegend (basal Permian) in Germany
2015
ABSTRACTTwo new species of Batropetes are described from the Lower Rotliegend of the Saar-Nahe Basin in western Germany. Batropetes palatinus, sp. nov., is characterized by a narrow, anteriorly elongated prefrontal, a slender postfrontal without an anterolateral process, a trapezoid postorbital, and a large quadrate in exterior view. Batropetes appelensis, sp. nov., is characterized by a high angular, ‘Z’-shaped angular-dentary suture, no indentation between stem and plate of interclavicle, and scapulocoracoid without ossified coracoid. The genus Batropetes is characterized by an average length of almost 8 cm, a short trunk with 17 or 19 presacrals depending on the species, large orbit with…
Polyphased mesozoic rifting from the Atlas to the north-west Africa paleomargin
2021
24 pages; International audience; Based on the interpretation of geological maps, seismic reflection and well data complemented with a bibliographic compilation and field work in the Rif, we investigate the factors that control the rift initiation, its development and the formation of oceanic crust in NW Africa. From SE to NW, we examine the Western Sahara Atlas, the Tendrara, the Guercif, and the Rif basins, to establish their geodynamic evolution in relation with the Mesozoic formation of the Central Atlantic and Maghrebian Tethys oceans, respectively. The Triassic extension was diffuse and developed over Lower Carboniferous horst-and-graben structures formed in the NW passive margin of G…
The Odonatoptera of the Late Permian Lodève Basin (Insecta).
2008
8 pages; International audience; The discovery of numerous and very diverse Odonatoptera in the Red Late Permian Lodève Basin questions its current reconstructions of a dry to very dry palaeoclimate and palaeoenvironment. It rather suggests the presence of more or less permanent water bodies, surrounded by a diversity of terrestrial biotas. The discovery of large to very large Meganeuridae contradicts the alleged relations between the decrease of body and wing sizes of the insects during the late Permian as a direct consequence of the decrease of the oxygen atmospheric concentrations at that time.
Microbial deposits in the aftermath of the end-Permian mass extinction: A diverging case from the Mineral Mountains (Utah, USA)
2015
40 pages; International audience; The Lower Triassic Mineral Mountains area (Utah, USA) preserves diversified Smithian and Spathian reefs and bioaccumulations that contain fenestral-microbialites and various benthic and pelagic organisms. Ecological and environmental changes during the Early Triassic are commonly assumed to be associated with numerous perturbations (productivity changes, acidifica-tion, redox changes, hypercapnia, eustatism and temperature changes) post-dating the Permian–Triassic mass extinction. New data acquired in the Mineral Mountains sediments provide evidence to decipher the relationships between depositional environments and the growth and distribution of microbial …
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 …
Long-term lacustrine paleo-productivity and/or paleo-anoxia trends controlled by eccentricity cycles in the continental Autun Basin (France) at the C…
2020
<p>The organic-rich lacustrine beds of the Autun Basin (France) were deposited from the late Gzhelian (late Carboniferous) to the Sakmarian (early Permian), encompassing the Carboniferous-Permian boundary (∼299 Ma). Those deposits reach up to 1500 m thick, and correspond to a tropical, intra-mountainous late-orogenic basin infilling associated with the Variscan orogeny (Marteau, 1983; Schneider et al., 2006). Organic-rich and laminated facies are attributed to distal lacustrine environments which sometimes alternate with silty to sandy rich deltaic depositional environments (Mercuzot et al., 2019). The four successive formations (respectively the Igornay, Muse, …
Early oysters and their supposed Permian ancestors
2005
The origin of oysters is a much debated palaeontological issue. Recent morphological studies indicate that oysters are characterized by a particular ribbing pattern, the so-called antimarginal ribs which are characterized by a proper morphogenetic pattern. Therefore antimarginal ribs can be used as a diagnostic character in phylogeny. The earliest recognized bivalve displaying diagnostic features of oysters (sinistral attachment to the substrate, typical hinge and ligament structure, and antimarginal ribs) is Ostracites cristadifformis Schlotheim, 1820 first appearing in the Anisian of Europe. This common species was later attributed to Enantiostreon and is here transferred to Umbrostrea. S…
Chirotheria and Other Ichnotaxa of the European Triassic
2004
At the end of the Permian, numerous amphibians and therapsids vanished, creating many empty ecological niches, which were occupied by new creatures. This event brought new trends in animal locomotion thanks to modifications of the skeleton limbs. The newcomers were faster and more dangerous for other families. The prominent ichnogenera were Synaptichnium, Chirotherium, Brachychirotherium, Isochirotherium, and Sphingopus. Their trackmakers were Thecodonts, reptiles having the above-mentioned evolutive characteristics. Dinosaurs, which appeared at the end of the Triassic period, were likely their descendants, which raises the question of when and where the dinosaurs originated. The comparison…