This review has been undertaken in order to present some interpretations about the biostratigraphy of the smaller foraminifers belonging to four classes present during the Permian: Fusulinata, Miliolata, Nodosariata and Textulariata. Biostratigraphic markers of these classes are principally known in the orders and superfamilies of Lasiodiscoidea, Bradyinoidea and Globivalvulinoidea (Fusulinata), Cornuspirida (Miliolata), and in the entire class Nodosariata. The class Textulariata is too little known during the Permian to play a significant biostratigraphical role: nevertheless, the appearance of the order Verneulinida is probably an important bioevent. The main genera among the lasiodiscids are Mesolasiodiscus, Lasiodiscus, Lasiotrochus, Asselodiscus, Pseudovidalina, Xingshandiscus and Altineria; the bradyinoids Bradyina and Postendothyra; the globivalvulinoids Globivalvulina, Septoglobivalvulina, Labioglobivalvulina, Paraglobivalvulina, Sengoerina, Dagmarita, Danielita, Louisettita, Paradagmarita, Paradagmaritopsis and Paremiratella; the miliolates Rectogordius, Okimuraites, Neodiscus, Multidiscus, Hemigordiopsis, Lysites, Shanita and Glomomidiellopsis, and the tubiphytids and ellesmerellids, which might be specialized miliolate and cyanobacterium consortia, with reference to microstructures and phylogenies of these groups. The Nodosariata markers belong to Nodosinelloides, Tezaquina, Polarisella, Geinitzina, Pachyphloia, Rectoglandulina, first true Nodosaria, Langella, Pseudolangella, Calvezina, Cryptoseptida, Cylindrocolaniella, Colaniella, Frondina and Ichthyofrondina, but their lineages are too poorly understood to permit an accurate biostratigraphic use at the present time. The superfamily Geinitzinoidea is emended. Finally, palaeobiogeographical implications based on Shanita, Colaniella and Altineria are given.
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The Permian Timescale
CONTAINS OPEN ACCESS
The Palaeozoic Era ends with the c. 47-million-year-long Permian Period. This was a major juncture in Earth history when the vast Pangean supercontinent continued its assembly and the global biota suffered the most extensive biotic decimation of the Phanerozoic, the end-Permian mass extinction. It was also the time of accumulation of vast mineral and energy deposits, notably of salt and petroleum. The temporal ordering of geological and biotic events during Permian time is, therefore, critical to the interpretation of some unique and pivotal events in Earth history. This temporal ordering is based mostly on the Permian timescale, which has been developed and refined for nearly two centuries. This book reviews the history of the development of the Permian chronostratigraphic scale. It also includes comprehensive analyses of Permian radioisotopic ages, magnetostratigraphy, isotope-based correlations, and timescale-relevant marine and non-marine biostratigraphy and biochronology.