Silurian cyathaspidid heterostracans of Northern Eurasia

Silurian cyathaspidid heterostracans discovered from the East Baltic, North Timan, the Central and Southern Urals, and the Novaya Zemlya and Severnaya Zemlya archipelagoes in 1970‒2006 were studied. Earlier known taxa Archegonaspis schmidti (Geinitz, 1884), Archegonaspis lindstroemi Kiaer, 1932, Arc...

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Bibliographic Details
Published in:Estonian Journal of Earth Sciences
Main Author: Tiiu Märss
Format: Article in Journal/Newspaper
Language:English
Published: Estonian Academy Publishers 2019
Subjects:
Online Access:https://doi.org/10.3176/earth.2019.11
https://doaj.org/article/7d59b7a5e3e643b2af0b6bb46cff5808
Description
Summary:Silurian cyathaspidid heterostracans discovered from the East Baltic, North Timan, the Central and Southern Urals, and the Novaya Zemlya and Severnaya Zemlya archipelagoes in 1970‒2006 were studied. Earlier known taxa Archegonaspis schmidti (Geinitz, 1884), Archegonaspis lindstroemi Kiaer, 1932, Archegonaspis integra (Kunth, 1872) and Tolypelepis undulata Pander, 1856 were identified and described. Archegonaspis bimaris Novitskaya, 1970 is synonymized under A. schmidti (Geinitz) and Tolypelepis mielnikensis Dec, 2015 under Tolypelepis undulata Pander, 1856. Three new taxa, Archegonaspis bashkirica sp. nov., Cyathaspis alexanderi sp. nov. and Tolypelepis bedovensis sp. nov., were established, while two taxa, Archegonaspis lindstroemi? Kiaer and Tolypelepis sp. indet., remained in open nomenclature. The new subfamily Archegonaspidinae subfam. nov. was created. It is shown that besides details of the morphology of shields and plates, sculpture characteristics can be utilized in taxonomy. The material described complements the taxonomic content as well as the spatio-temporal distribution data of the species of the family Cyathaspididae.