The Wenlock Cyrtograptus species of the Builth Wells District, central Wales
The Wenlock sequence of the Builth Wells district, central Wales is dominated by long‐ranging Monograptus , Pristiograptus and Monoclimacis species. Cyrtograptus species, which underpin the graptolite biozonation, represent only about 10 per cent of recovered individuals. Ten Cyrtograptus species ar...
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crwiley:10.1111/j.0031-0239.2004.00372.x 2024-09-09T19:26:00+00:00 The Wenlock Cyrtograptus species of the Builth Wells District, central Wales Williams, Mark Zalasiewicz, Jan 2004 http://dx.doi.org/10.1111/j.0031-0239.2004.00372.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.0031-0239.2004.00372.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.0031-0239.2004.00372.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Palaeontology volume 47, issue 2, page 223-263 ISSN 0031-0239 1475-4983 journal-article 2004 crwiley https://doi.org/10.1111/j.0031-0239.2004.00372.x 2024-07-25T04:21:17Z The Wenlock sequence of the Builth Wells district, central Wales is dominated by long‐ranging Monograptus , Pristiograptus and Monoclimacis species. Cyrtograptus species, which underpin the graptolite biozonation, represent only about 10 per cent of recovered individuals. Ten Cyrtograptus species are present, most being zonal index species for the Builth district or other Wenlock sequences. Redescription of these Cyrtograptus species and comparison with all pertinent type material indicates that: the early Wenlock Cyrtograptus insectus , C. centrifugus and C. murchisoni are best distinguished by means of first whorl diameter, sicula length and differences of cladial development; mid Wenlock Cyrtograptus rigidus may bear a secondary cladium, but at Builth there are no stratigraphically discrete subspecies; Cyrtograptus linnarssoni is known only from its type locality; the long, gracile proximal part of the rhabdosome of C. ellesae facilitates its distinction from C. perneri , with which it has been confused, and indicates similarities to C. ramosus and C. lundgreni . Differences in the ranges of key Cyrtograptus species present problems for correlation between the lundgreni Biozone of the Builth district and the perneri‐ramosus and lundgreni biozones of central Europe. The low diversity and abundance of the cyrtograptid fauna of the Builth district, compared to those of Arctic Canada and the Czech Republic, suggests relatively inhospitable conditions for graptolites. Article in Journal/Newspaper Arctic Wiley Online Library Arctic Canada Palaeontology 47 2 223 263 |
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Wiley Online Library |
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language |
English |
description |
The Wenlock sequence of the Builth Wells district, central Wales is dominated by long‐ranging Monograptus , Pristiograptus and Monoclimacis species. Cyrtograptus species, which underpin the graptolite biozonation, represent only about 10 per cent of recovered individuals. Ten Cyrtograptus species are present, most being zonal index species for the Builth district or other Wenlock sequences. Redescription of these Cyrtograptus species and comparison with all pertinent type material indicates that: the early Wenlock Cyrtograptus insectus , C. centrifugus and C. murchisoni are best distinguished by means of first whorl diameter, sicula length and differences of cladial development; mid Wenlock Cyrtograptus rigidus may bear a secondary cladium, but at Builth there are no stratigraphically discrete subspecies; Cyrtograptus linnarssoni is known only from its type locality; the long, gracile proximal part of the rhabdosome of C. ellesae facilitates its distinction from C. perneri , with which it has been confused, and indicates similarities to C. ramosus and C. lundgreni . Differences in the ranges of key Cyrtograptus species present problems for correlation between the lundgreni Biozone of the Builth district and the perneri‐ramosus and lundgreni biozones of central Europe. The low diversity and abundance of the cyrtograptid fauna of the Builth district, compared to those of Arctic Canada and the Czech Republic, suggests relatively inhospitable conditions for graptolites. |
format |
Article in Journal/Newspaper |
author |
Williams, Mark Zalasiewicz, Jan |
spellingShingle |
Williams, Mark Zalasiewicz, Jan The Wenlock Cyrtograptus species of the Builth Wells District, central Wales |
author_facet |
Williams, Mark Zalasiewicz, Jan |
author_sort |
Williams, Mark |
title |
The Wenlock Cyrtograptus species of the Builth Wells District, central Wales |
title_short |
The Wenlock Cyrtograptus species of the Builth Wells District, central Wales |
title_full |
The Wenlock Cyrtograptus species of the Builth Wells District, central Wales |
title_fullStr |
The Wenlock Cyrtograptus species of the Builth Wells District, central Wales |
title_full_unstemmed |
The Wenlock Cyrtograptus species of the Builth Wells District, central Wales |
title_sort |
wenlock cyrtograptus species of the builth wells district, central wales |
publisher |
Wiley |
publishDate |
2004 |
url |
http://dx.doi.org/10.1111/j.0031-0239.2004.00372.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.0031-0239.2004.00372.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.0031-0239.2004.00372.x |
geographic |
Arctic Canada |
geographic_facet |
Arctic Canada |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
Palaeontology volume 47, issue 2, page 223-263 ISSN 0031-0239 1475-4983 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.0031-0239.2004.00372.x |
container_title |
Palaeontology |
container_volume |
47 |
container_issue |
2 |
container_start_page |
223 |
op_container_end_page |
263 |
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1809895713665974272 |