The Cambrian Burgess Shale-type biotas form a globally consistent ecosystem, usually dominated by arthropods. Elements of these communities continued into the Early Ordovician at high latitude, but our understanding of ecological changes during the Great Ordovician Biodiversification Event (GOBE) is currently limited by the paucity of Ordovician exceptionally preserved open-marine faunas. Here ...

A new compilation of fossil data on invertebrate and vertebrate families indicates that four mass extinctions in the marine realm are statistically distinct from background extinction levels. These four occurred late in the Ordovician, Permian, Triassic, and Cretaceous periods. A fifth extinction event in the Devonian stands out from the background but is not statistically significant in these ...

We report new discoveries of embryos and egg capsules from the Lower Cambrian of Siberia, Middle Cambrian of Australia and Lower Ordovician of North America. Together with existing records, embryos have now been recorded from four of the seven continents. However, the new discoveries highlight secular and systematic biases in the fossil record of embryonic stages. The temporal window within whi...

Abstrac.t-Based on the intensity and rates of various kinds of intense ionizing radiation events such as supernovae and gamma-ray bursts, it is likely that the Earth has been subjected to one or more events of potential mass extinction level intensity during the Phanerozoic. These induce changes in atmospheric chemistry so that the level of Solar ultraviolet-B radiation reaching the surface and...

The Ordovician System, cropping out in southern and west-central Jordan, consists entirely of a 750 m thick clastic sequence that can be subdivided into six formations. The lower Disi Formation starts conformably above the Late Cambrian Umm Ishrin Formation. According to Cruziana furcifera occurring in the upper third of the Disi Formation, an Early Ordovician age is con®rmed. The Disi Formatio...

Abstract It remains unclear whether waning of the volcanic degassing CO2 source or enhancement mafic (Ca, Mg-silicate) weathering sink, both, caused global cooling leading to Ordovician greenhouse–icehouse transition. We present a uniquely age-constrained and integrated Middle–Late (470–450 Ma) continental isotopic proxy data set (87Sr/86Sr ?Nd(t)) from carbonate rocks Antelope Range central Ne...

This report provides oxygen isotopes from apatite of late Middle and Late Ordovician conodonts the southern Holy Cross Mountains in south-eastern Poland. It was a unique time interval characterised by significant change climate, tectonic, ocean chemistry. In early Ordovician, were located mid-latitude climatic zone at southwestern periphery Baltica; therefore, δ18Oapatite values this region pro...

Strike-slip deformation belts are interesting structures in the crust and of significance petroleum exploration. The Shunbei 5 fault belt (SB5), a long strike-slip Tarim Basin, played an important role formation recently discovered major oilfield known as oilfield. In this study, models plan view vertical profile were established to interpret SB5 with multi-cycled tectonic activities. To end, i...