Four volcanic-ash beds bracket the Early-Middle Triassic boundary, as defined by conodont biostratigraphy, in a stratigraphic section in south China. High-precision U-Pb dates of single zircons allow us to place the Early to Middle Triassic (Olenekian-Anisian) boundary at 247.2 Ma. Magnetic-reversal stratigraphy allows global correlation. The new dates constrain the Early Triassic interval char...

The family Mesopanorpodidae is revised. Most taxa referred to this family are not related to the type genus Mesopanorpodes Tillyard, 1918. The type species of the latter, Mesopanorpodes wianamattensis,is closely related to Mesopsyche Tillyard, 1917. Therefore Mesopanorpodes is transferred to Mesopsychidae Tillyard, 1917 (= Mesopanorpodidae Tillyard, 1918, syn. n.).The earliest Mesopsychidae are...

Early Triassic animal body fossils and trace fossils are small relative to those in older and younger intervals. Size decreases sharply through the end-Permian extinction event and Permian/Triassic boundary, and the smallest sizes are encountered in the parvus and isarcica Zones of the earliest Induan. Animals appearing within these two zones are also exceedingly small, compared to younger cong...

Arsenic is one of the toxic trace elements in coals, which is harmful to both the ecological environment and human health. Based on published literature and the data obtained by our research group, a total of 5314 As concentrations of Chinese coals were analyzed. The arithmetic mean of arsenic content in Chinese coals is 6.97 mg/kg. Choosing the percentage of provincial coal resources in nation...

A new replacement name Permulidaenom. n. is proposed for the Permian family Aliculidae Storozhenko, 1997 (Insecta: Grylloblattida). A review of Permulidae is given. All genera and species are redescribed and illustrated. A key to genera of Permulidae is given. New taxa of Permulidae are described: Permula edemskiisp. n., Sojanopermula rasnitsynisp. n., Kazanalicula reductagen. et sp. n., Mezena...

The arsenic concentrations in 297 coal samples were collected from the main coal-mines of 26 provinces in China were determined by molybdenum blue coloration method. These samples were collected from coals that vary widely in coal rank and coal-forming periods from the five main coal-bearing regions in China. Arsenic content in Chinese coals range between 0.24 to 71 mg/kg. The mean of the conce...

BACKGROUND Several clades of bivalve molluscs have invaded freshwaters at various times throughout Phanerozoic history. The most successful freshwater clade in the modern world is the Unionoida. Unionoids arose in the Triassic Period, sometime after the major extinction event at the End-Permian boundary and are now widely distributed across all continents except Antarctica. Until now, no freshw...

The Permian–Triassic boundary at Nhi Tao, Cao Bang Province, Vietnam was sampled in a 7.5-m-thick outcrop section at high resolution (∼5 cm intervals) for chemostratigraphic and magnetic susceptibility analysis. The section consists entirely of slightly argillaceous limestone representing shallow-marine facies of the Jinxi Platform, one of several large carbonate platforms within the Nanpanjian...

Multiple chondritic meteorite fragments have been found in two sedimentary rock samples from an end-Permian bed at Graphite Peak in Antarctica. The Ni/Fe, Co/Ni, and P/Fe ratios in metal grains; the Fe/Mg and Mn/Fe ratios in olivine and pyroxene; and the chemistry of Fe-, Ni-, P-, and S-bearing oxide in the meteorite fragments are typical of CM-type chondritic meteorites. In one sample, the met...

Late Permian coal deposits are widely distributed throughout southwestern China. This paper describes the petrological composition of last seam in Longmendong section Emeishan area during latest Changhsingian (Permian) and records important information regarding evolution mass extinction event that occurred at end Permian. The results show dominant maceral group is vitrinite, followed by liptin...