Taxonomy and Evolution of Visean-Roadian (Late Mississippian-Guadalupian) Lasiodiscidae

Abstract

© 2020 Cushman Foundation. All rights reserved. The study of the test morphology of type specimens and newly collected foraminiferal material of the family Lasiodiscidae Reitlinger, 1956, from the Carboniferous (Visean Stage, Mississippian Subsystem) to Permian (Roa-dian Stage, Guadalupian Series) beds of Russia (East Euro-pean Platform and Urals), Turkey, and Tajikistan (Darvaz) allowed a revision of the species composition of the genera Honchinia, Monotaxirtoides, Eolasiodiscus, Turrispiroides, and Mesolasiodiscus. A new genus, Postmonotaxinoides, is described. The species Monotaxirtoides transitorius, M. suhplanus, M. gracilis, Eolasiodiscus donbassicus, E. galinae, Mesolasiodiscus tenuis, M. nigrans, Postmonotaxinoides horridus, P. costiferus, and P. grandis are redescribed based on new data of their test morphology. Their taxonomy is revised and new phylogenetic reconstructions for the pecies are proposed.