The oldest bifoliate cystoporate and two other bryozoan taxa from the Dapingian (Middle Ordovician) of north-western Russia
Abstract Bryozoans from the Dapingian (Middle Ordovician) of the Baltic paleobasin remain poorly studied and their taxonomic composition is unclear. In this paper, three bryozoan taxa, a bifoliate cystoporate Planopora volkhovensis n. gen. n. sp., a trepostome Hemiphragma insolitum n. sp., and an es...
Published in: | Journal of Paleontology |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Cambridge University Press (CUP)
2020
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1017/jpa.2020.73 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022336020000736 |
id |
crcambridgeupr:10.1017/jpa.2020.73 |
---|---|
record_format |
openpolar |
spelling |
crcambridgeupr:10.1017/jpa.2020.73 2024-03-03T08:47:17+00:00 The oldest bifoliate cystoporate and two other bryozoan taxa from the Dapingian (Middle Ordovician) of north-western Russia Koromyslova, Anna V. Fedorov, Petr V. 2020 http://dx.doi.org/10.1017/jpa.2020.73 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022336020000736 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Journal of Paleontology volume 95, issue 1, page 24-39 ISSN 0022-3360 1937-2337 Paleontology journal-article 2020 crcambridgeupr https://doi.org/10.1017/jpa.2020.73 2024-02-08T08:33:54Z Abstract Bryozoans from the Dapingian (Middle Ordovician) of the Baltic paleobasin remain poorly studied and their taxonomic composition is unclear. In this paper, three bryozoan taxa, a bifoliate cystoporate Planopora volkhovensis n. gen. n. sp., a trepostome Hemiphragma insolitum n. sp., and an esthonioporate Esthoniopora clara Koromyslova, are described from Dapingian deposits of an unusual clayey-calcareous Hecker-type mudmound on the right bank of the Volkhov River in Leningrad Oblast’, north-western Russia. Combined X-ray microtomography, scanning electron microscopy, and light microscopy of thin sections were used to characterize their morphology. Analysis of the stratigraphic distribution of early cystoporate bryozoans suggests that Planopora n. gen. is the oldest сystoporate bryozoan with an erect, bifoliate colony. The growth modes of these bryozoans are discussed. The colonies of P . volkhovensis n. gen. n. sp. and E . clara have an attachment structure, a holdfast, at their base, probably indicating their attachment to sponge spicules. The bryozoan H . insolitum n. sp. produced rod-like colonies, formed by overgrowing the problematic tubular fossil Sphenothallus Hall. It can be assumed that sponges with unfused siliceous spicules and individuals of Sphenothallus were numerous on the surface of the mudmound during its formation and provided a suitable substrate for settlement of bryozoan larvae. UUID: http://zoobank.org/5715872a-8c61-446e-9413-d713fdef1a08 Article in Journal/Newspaper North-Western Russia Cambridge University Press Holdfast ENVELOPE(-66.590,-66.590,-66.803,-66.803) Journal of Paleontology 95 1 24 39 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Paleontology |
spellingShingle |
Paleontology Koromyslova, Anna V. Fedorov, Petr V. The oldest bifoliate cystoporate and two other bryozoan taxa from the Dapingian (Middle Ordovician) of north-western Russia |
topic_facet |
Paleontology |
description |
Abstract Bryozoans from the Dapingian (Middle Ordovician) of the Baltic paleobasin remain poorly studied and their taxonomic composition is unclear. In this paper, three bryozoan taxa, a bifoliate cystoporate Planopora volkhovensis n. gen. n. sp., a trepostome Hemiphragma insolitum n. sp., and an esthonioporate Esthoniopora clara Koromyslova, are described from Dapingian deposits of an unusual clayey-calcareous Hecker-type mudmound on the right bank of the Volkhov River in Leningrad Oblast’, north-western Russia. Combined X-ray microtomography, scanning electron microscopy, and light microscopy of thin sections were used to characterize their morphology. Analysis of the stratigraphic distribution of early cystoporate bryozoans suggests that Planopora n. gen. is the oldest сystoporate bryozoan with an erect, bifoliate colony. The growth modes of these bryozoans are discussed. The colonies of P . volkhovensis n. gen. n. sp. and E . clara have an attachment structure, a holdfast, at their base, probably indicating their attachment to sponge spicules. The bryozoan H . insolitum n. sp. produced rod-like colonies, formed by overgrowing the problematic tubular fossil Sphenothallus Hall. It can be assumed that sponges with unfused siliceous spicules and individuals of Sphenothallus were numerous on the surface of the mudmound during its formation and provided a suitable substrate for settlement of bryozoan larvae. UUID: http://zoobank.org/5715872a-8c61-446e-9413-d713fdef1a08 |
format |
Article in Journal/Newspaper |
author |
Koromyslova, Anna V. Fedorov, Petr V. |
author_facet |
Koromyslova, Anna V. Fedorov, Petr V. |
author_sort |
Koromyslova, Anna V. |
title |
The oldest bifoliate cystoporate and two other bryozoan taxa from the Dapingian (Middle Ordovician) of north-western Russia |
title_short |
The oldest bifoliate cystoporate and two other bryozoan taxa from the Dapingian (Middle Ordovician) of north-western Russia |
title_full |
The oldest bifoliate cystoporate and two other bryozoan taxa from the Dapingian (Middle Ordovician) of north-western Russia |
title_fullStr |
The oldest bifoliate cystoporate and two other bryozoan taxa from the Dapingian (Middle Ordovician) of north-western Russia |
title_full_unstemmed |
The oldest bifoliate cystoporate and two other bryozoan taxa from the Dapingian (Middle Ordovician) of north-western Russia |
title_sort |
oldest bifoliate cystoporate and two other bryozoan taxa from the dapingian (middle ordovician) of north-western russia |
publisher |
Cambridge University Press (CUP) |
publishDate |
2020 |
url |
http://dx.doi.org/10.1017/jpa.2020.73 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022336020000736 |
long_lat |
ENVELOPE(-66.590,-66.590,-66.803,-66.803) |
geographic |
Holdfast |
geographic_facet |
Holdfast |
genre |
North-Western Russia |
genre_facet |
North-Western Russia |
op_source |
Journal of Paleontology volume 95, issue 1, page 24-39 ISSN 0022-3360 1937-2337 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/jpa.2020.73 |
container_title |
Journal of Paleontology |
container_volume |
95 |
container_issue |
1 |
container_start_page |
24 |
op_container_end_page |
39 |
_version_ |
1792503439722283008 |