Extinctions within major pelagic groups (e.g., radiolarians and conodonts) occurred in a stepwise fashion during the last 15 Myr of the Triassic. Although a marked decline in the diversity of pelagic faunas began at the end of the middle Norian, the cause of the middle Norian extinction is uncertain. Here we show a possible link between the end-middle Norian radiolarian extinction and a bolide ...

The ancient marine limestone beds of the upper part of the Guanling Formation, Panxian County, Guizhou Province, SW China, yielded a wide range of high-diversity wellpreserved marine reptiles such as the fully aquatic protorosaur with an extremely long neck Dinocephalosaurus orientalis, the oldest mixosaurid ichthyosaurs and lariosaurs. However, there is no precise isotopic age to study the int...

conodonts of khoshyeilagh formation, the most complete section of devonian rocks in the alborz mountains, northern iran, has been studied, and subspecies of the genera icriodus, bipennatus, polygnathus, pelekysgnathus, ancyrodella, palmatolepis, bispathodus, scaphignathus, clydagnathus, gnathodus, scaliognathus and dollymae have been obtained from the studied section. the faunas indicate an eif...

A new conodont species, Icriodus marieae, is described from pelagic limestone beds of the Carnic Alps (Austria). Specimens are obtained from the upper part of the Valentin Formation (Central Carnic Alps) and range from the latest Eifelian to middle Givetian. Significantly differing from other icriodontid conodonts is that the icriodontan element of the new species develops only three denticles ...

The zonal scheme of the Givetian-Frasnian boundary interval in Timan-Northern Urals region was detailed according to higher plants spores. Palynological zones were correlated with faunal, including conodont — orthostratigraphic group Devonian. correlation identified critical boundaries development plant communities divisions’ borders International Stratigraphic Scale series and stages, establis...

The Permian-Triassic boundary in the Himalayas is reviewed and discussed in the light of palaeontologic and stratigraphic data collected during the past two and a half decades from Kashmir, Spiti and Nepal. The deposition of the Kuling Shales and their equivalents in different parts of the Himalayas was followed by shallowing and regression of the sea. Sedimentation was interrupted at the t...