Microsculpture Study of Late Permian and Early Triassic Conchostracans From the Babii Kamen Section (Western Siberia)

Abstract

The microsculpture of Permian and Triassic conchostracans from the Babii Kamen section (Western Siberia) was studied in order to determine the significance of microsculpture inthe taxonomy of conchostracan species. Five types of ornamentation have been identified in conchostracans from the Permian-Triassic reference section of Western Siberia (Babii Kamen section): pitted, nodular, reticulated, radial lirae, radial fringes. The results show that several microsculpture types are common for the genus level of conchostracans. Transition from one type of ornamentation to another was noted in three species: ?Megasitum lopokolense Novojilov, 1970, "Cornia papillaria" Lutkevich, 1937, and "Concherisma tomensis" Novojilov, 1958. The observed changes in the shell microsculpture types can be considered as a taxonomic feature for these three species and should form the base for future taxonomical revisions.

An Early Devonian clam shrimp community from Hunan Province, China

“…In addition, a specimen identified as “ C . papillaira ” (Lutkevich, 1937) from the Maltsevo Formation in the Babiy Kamen section of Siberia displayed a transition of reticulations and lirae on its carapace (Sabirova et al, 2019). Unfortunately, no useful ornamentation was found in our specimens due to poor preservation.…”

“…P . itiliana Novojilov, 1950, from the Cheremushka Ravine section in Russia, are ornamented with reticulations (Zharinova et al, 2018; Sabirova et al, 2019).…”