Late Permian conchostracans (Crustacea, Branchiopoda) from continental deposits in the Moscow Syneclise, Russia

Abstract

The Moscow Syneclise on the East European Platform is an important area for the study of the continental biota of late Permian to Early Triassic age in continuous sections. This study attempts a taxonomic description of the late Permian conchostracan fauna of this area. The rich, new material was collected, bed by bed, during geological and paleontological excavations of lacustrine and fluvial deposits of the Obnora Formation and Vokhma Formation of the late Permian Zhukovian Regional Stage near the towns of Vyazniki and Gorokhovets. The conchostracan fauna of the Zhukovian Regional Stage consists predominantly ofPseudestheriaand less frequently ofPalaeolimnadiopsis. In the earliest Triassic Vokhmian Regional Stage, a more diverse fauna includingEuestheria,Magniestheria,Cornia,Palaeolimnadiopsis, andRossolimnadiopsiswas already recorded. The preliminary taxonomic determination of the pseudestheriids from the Zhukovian Regional Stage is intended to serve as a prerequisite for future studies of late Permian conchostracan biostratigraphy on the regional to interregional scale.

Biostratigraphic significance and geometric morphometrics of Euestheria gutta (Crustacea: Branchiopoda: Spinicaudata): An index fossil of continental Permian–Triassic transitional beds

“…E. gutta was reported from the Fulda, Calvörde, and Bernberg formations in central Germany (Kozur & Seidel, 1983a, 1983b; Kozur & Weems, 2010), and these have been verified by subsequent studies (Scholze et al, 2016; Scholze et al, 2017), though the age of its first appearance is controversial. Recently, E. gutta were reported from the Kayitou Formation in southwestern China (Chu et al, 2013; Chu et al, 2016; Scholze et al, 2019). Furthermore, Scholze et al (2015) documented E .…”

“…gutta was reported from the Fulda, Calvörde, and Bernberg formations in central Germany (Kozur & Seidel, 1983a, 1983bKozur & Weems, 2010), and these have been verified by subsequent studies (Scholze et al, 2016;Scholze et al, 2017), though the age of its first appearance is controversial. Recently, E. gutta were reported from the Kayitou Formation in southwestern China (Chu et al, 2013;Chu et al, 2016;Scholze et al, 2019). Furthermore, Scholze et al (2015) documented E. gutta in association with Magniestheria mangaliensis from the Vokhma Formation (Vokhmian Regional Stage; Early Triassic) in the Moscow Syncline, and a similar spinicaudatan assemblage also appeared in North China (Chu et al, 2019).…”

“…Spinicaudatans are some of the most common fossils in continental strata since the Devonian, and their wide distribution and fast evolution means they can be used as effective tools for continental stratigraphic division and correlation (Huang, 2019; Kozur & Weems, 2010; Morton, Whiteside, Hethke, & Benton, 2017; Schneider et al, 2020; Schneider & Scholze, 2016; Tasch & Volkheimer, 1970). Recently, spinicaudatan biostratigraphy has been attempted for continental P–Tr transitional strata, based on their worldwide distribution, including Russia, western Europe, northwestern China, and South China (Chu et al, 2016; Chu, Tong, Yu, Song, & Tian, 2013; Kozur & Weems, 2011; Schneider et al, 2020; Schneider & Scholze, 2016; Scholze et al, 2015; Scholze et al, 2016; Scholze, Golubev, Niedźwiedzki, Schneider, & Sennikov, 2019). In particular, some species were discovered in the latest Permian, earliest Triassic, or Permian–Triassic transitional strata from various basins, such as South China, North China, Germanic Basin, and Moscow Syncline (Chu et al, 2016; Chu et al, 2019; Kozur & Seidel, 1983a, 1983b; Scholze et al, 2015; Scholze et al, 2016).…”

“…And they may be of biostratigraphic significance. In particular, Euestheria gutta has been reported repeatedly and shows potential as the index fossil of P–Tr transitional strata, though the time range of this species has been debated, as it has been thought to be latest Permian, earliest Triassic, or Permian–Triassic transitional in age (Chu et al, 2013; Chu et al, 2016; Scholze et al, 2015; Scholze et al, 2016; Scholze et al, 2019). Herein, we explore the biostratigraphic significance of E. gutta and the temporal relationship between occurrences of this species and other fossils based on well‐preserved records from southwestern China.…”

An Early Devonian clam shrimp community from Hunan Province, China

“…However, the spines on the larval valves of some corniids also could appear to be oval to round when the carapaces are heavily compacted. But it should be noted that the larval valves of lioestheriids are usually larger than one-third of the valves’ length (Holub and Kozur, 1981; Kozur and Sittig, 1981; Scholze et al, 2019). Larval valves of this new species are obviously not that large, hence we assign it to Cornia instead of Lioestheria .…”