Quick
Search: 		  
advanced search
 GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help 
Micropaleontology Don't get GSW? Talk to your librarian.
JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Micropaleontology; March 2005; v. 51; no. 1; p. 83-91; DOI: 10.2113/51.1.83
© 2005 Micropaleontology Project
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Umeda, M.
Right arrow Articles by Suzuki, Y.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation

Article

Aeronian (Llandovery, Early Silurian) Radiolarians from the Kallholn Formation in Siljan district, Sweden

Masaki Umeda1 and Yutaro Suzuki2

1 Higashiosaka College, Nishizutsumigakuencho, Higashiosaka, Osaka 577-8567, Japan, email: umeda{at}higashiosaka.ac.jp
2 Institute of Geosciences, Shizuoka University, Ohya, Shizuoka 422-8529, Japan, email: sysuzuk{at}ipc.shizuoka.ac.jp

Early Aeronian (middle Llandovery, Early Silurian) radiolarians collected from calcareous nodules of the Kallholn Formation in the Siljan district, Sweden, are described. Seven genera and 11 species, including one new family Gyrosphaeridae and two new species, Palaeoscenidium kuriharai and Gyrosphaera primigena, are described. This fauna is characterized by the dominance of large spherical radiolarians, which constitute 54% of the total number of specimens per nodule. The fauna is similar to the middle Telychian fauna insofar as it is dominated by Haplotaeniatum cathenatum. However, it can be distinguished from the late Rhuddanian fauna by the sparse occurrence of H. aperturatum. These data suggest that the period from the Aeronian to the middle Telychian was marked by the dominance of H. cathenatum.

Radiolarian spines, a morphological innovation, are believed to have evolved in the Aeronian. The time of radiolarian diversification corresponds to that of other planktonic/nektonic faunas including graptolites, chitinozoans, and fish, which suggests that marine macroplanktonic/nektonic faunas and microplankton diversified simultaneously in the Aeronian.






JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2009 by Micropaleontology Project