Glacial episodes have been linked to Ordovician-Silurian extinction events, but cooling itself may not be solely responsible for these extinctions. Teratological (malformed) assemblages of fossil plankton that correlate precisely with the extinction events can help identify alternate drivers of extinction. Here we show that metal poisoning may have caused these aberrant morphologies during a la...

Cladistic parsimony analysis of the subfamily Deiphoninae Raymond, 1913 was conducted to produce a hypothesis of relationship for the group. The genera Deiphon Barrande, 1850 and Onycopyge Woodward, 1880 are found to be monophyletic, while the genus Sphaerocoryphe Angelin, 1854, as it was previously defined, is paraphyletic. A modified Brooks Parsimony Analysis using the phylogenetic hypothesis...

In order to obtain a Lower Palaeozoic pole for the Armorican Massif and to test the origin of the Ibero-Armorican arc, the Ordovician dolerites of the Crozon peninsula have been palaeomagnetically studied. The samples show a multicomponent magnetization which has been revealed by AF and thermal demagnetization and thoroughly investigated with rock magnetic experiments, polished section examinat...

In the Ennedi Plateau, northeastern Chad, Cambrian(?)–Ordovician to Carboniferous strata represent one of most proximal succession north-facing Gondwana platform. This study presents preliminary results related c. 200 m-thick Lower Sandstones and overlying Bedo Formation, which essentially record Early Middle Ordovician flooding events end-Ordovician glaciation subsequent deglaciation. Sandston...

Detrital zircon populations of the South Qiangtang terrane (SQT) provide vital information for reconstructing Tethyan evolution Tibetan Plateau but are obscured by undefined affiliation detrital samples and superimposition multiple tectonothermal events. We outlined SQT based on geological mapping collated Cambrian-Triassic to investigate representative populations. Although diachronous strata ...