Correlation of Early Devonian (Lochkovian-early Pragian) conodont faunas of the South Urals (Russia)

Abstract

Carbonate successions of the early Lower Devonian (Lochkovian-early Pragian) from the Mindigulovo section (West Zilair Zone, western slope of the South Urals) can be globally correlated using diverse conodont faunas. The number of the documented widespread or cosmopolitan taxa of the Lochkovian and early Pragian age enables the definition of globally recognized conodont successions and the establishment of a refined regional conodont biozonal scale. The present three-fold global subdivision of the Lochkovian Stage can be applied as well to the studied area. The Lochkovian in the South Urals is represented by two Horizons (regional terminology) with different facies development: 1. The Siyak Horizon of the lower Lochkovian characterized by the dominance of shallow-water organogenic limestones of the hesperius-optima and optima-omoalpha Zones, and 2. The Sherlubai Horizon of the middle and upper Lochkovian age characterized by the dominance of carbonate-terrigenous successions. The middle and upper Lochkovian is subdivided into five biozones (using a binominal system): omoalpha-eoeleanorae, eoeleanorae-eleanorae, eleanorae-trigonicus, trigonicus-pandora beta and pandora beta-sulcatus eta/steinachensis. The Lochkovian-Pragian boundary and the early Pragian time are determined by the presence of eognathodontid and icriodontid stocks. The established regional conodont zonal scale in the South Urals provides a solid basis for refined correlation with the Lochkovian-early Pragian carbonate rocks of peri-Gondwana and Euramerica. •

Early Devonian polygnathids of Northeast Asia and correlation of Pragian/Emsian strata of the marginal seas of Angarida

“…At Royal Creek, Yukon Territory (Canada) P. exigua philipi and P. serratus have been found also together with "Spathognathodus sulcatus" (Klapper 1969). The age determination of the top of the Tomskiy Zavod and Peetz Suite (Bakharev et al 2013) as eurekaensis Zone is not clear, because the index species of the zone has been recognized only locally in Nevada and is no longer used worldwide (e.g., Murphy & Valenzuela-Ríos 1999, Corradini & Corriga 2012, Slavík et al 2012, Drygant & Szaniawski 2012, Mavrinskaya & Slavík 2013. The conodonts reported recently by Bakharev et al (2013) are not decisive for the early Lochkovian age.…”

Upper Silurian and Lower Devonian conodonts from Tafilalt, southeastern Morocco

“…Barrick et al 2005;Corriga 2011;Corriga et al 2011Corriga et al , 2012Slavík et al 2012;Drygant & Szaniawski 2012;Mavrinskaya & Slavík 2013), presenting data that can help in the reconstruction of the phylogenesis of Lanea and Ancyrodelloides (Fig. 7).…”

Editorial preface: IGCP 596, Mid-Paleozoic climate and biodiversity: Proceedings of the Opening Meeting in Graz, Austria (September 19–24, 2011)

“…Mavrinskaya & Slavík (2013) investigated Lochkovian-Pragian conodonts of the West Zilair Zone. They provide distribution patterns of conodont genera, which indicate that conodont diversity declined during the late Lochkovian pesavis Zone.…”