There are few sponges known from the end-Ordovician to early-Silurian strata all over the world, and no records of sponge fossils have been found yet in China during this interval. Here we report a unique sponge assemblage spanning the interval of the end-Ordovician mass extinction from the Kaochiapien Formation (Upper Ordovician-Lower Silurian) in South China. This assemblage contains a variet...

Calcareous skeletons evolved as part of the greater Ediacaran/Cambrian diversification of marine animals; however, skeletons did not become permanent, globally important sources of carbonate sediment until the Ordovician radiation. Representative carbonate facies in a Series 3 Cambrian to Tremadocian succession from western Newfoundland and Ordovician successions from the Ibex area, Utah, show ...

There was a major diversification known as the Ordovician Radiation, in the period immediately following the Cambrian. This event is unique in taxonomic, ecologic and biogeographic aspects.While all of the phyla but one were established during the Cambrian explosion, taxonomic increases during the Ordovician were manifest at lower taxonomic levels although ordinal level diversity doubled. Marin...

Abstract The Ordovician–Silurian (~485–419 Ma) was a time of considerable evolutionary upheaval, encompassing both great diversification and one the first major mass extinctions. Ordovician coincided with global climatic cooling paleocontinental collision, ecological impacts which were mediated by region-specific processes including substrate changes, biotic invasions, tectonic movements. From ...

The Caledonian basement crops out in the middle and southern part of Belgium two major tectonic units: Brabant Massif Parautochthon Stavelot-Venn, Rocroi, Givonne Serpont inliers Ardenne Allochthon. main aim this work is to achieve a chronostratigraphic correlation between inliers, from lower Cambrian Middle Ordovician. Throughout his career, Michel Vanguestaine established an informal acritarc...

To geologists, the Ordovician System of Ohio is probably the most famous of the state's Paleozoic rock systems. The alternating shales and limestones of the upper part of this system crop out in southwestern Ohio in the Cincinnati region and yield an incredible abundance and diversity of well-preserved fossils. Representatives of this fauna reside in museums and private collections throughout t...

The Ordovician biodiversification is considered one of the most significant radiations in marine ecosystems entire Phanerozoic. Originally recognized as ‘Ordovician Radiation’, a label retained during 1980s and 1990s, term ‘Great Biodiversification Event’ (GOBE) was coined late 1990s subsequently adopted by scientific community. biodiversification, has always been long-term adaptive radiation, ...

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...

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...