Early Ordovician (Floian) ostracods from the Cordillera Oriental, Northwest Argentina
Article first published online: 5 SEP 2011
Copyright © 2011 John Wiley & Sons, Ltd.
Volume 46, Issue 6, pages 637–650, November/December 2011
How to Cite
Salas, M. J. (2011), Early Ordovician (Floian) ostracods from the Cordillera Oriental, Northwest Argentina. Geol. J., 46: 637–650. doi: 10.1002/gj.1319
- Issue published online: 20 OCT 2011
- Article first published online: 5 SEP 2011
- Manuscript Accepted: 20 JUN 2011
- Manuscript Received: 17 JAN 2011
- Lower Ordovician;
- NW Argentina;
- Central Andean Basin
The ostracod fauna from the Floian (Lower Ordovician) strata of the Cordillera Oriental, Argentina (Acoite Formation) are documented. One new genus Acoitella and four species are recognized, two of which are new (Nanopsis victoria sp. nov. and Conchoprimitia frequens sp. nov.). The diversity of the Early Ordovician ostracod faunas of the Central Andean Basin is evaluated. Compared with other regions, the ostracod diversity, at generic and specific level, of the Cordillera Oriental was comparatively high during the Tremadocian (nine species recorded) and comparatively low during the Floian (four species recorded). The taxonomic composition of the fauna is similar during the entire Early Ordovician of the Cordillera Oriental, where it displays a high percentage of soanellids. The Floian assemblages are characterized by the dominance of the eridostracan C. frequens sp. nov. with a high percentage of nondimorphic palaeocopids: Nanopsis and two genera of the Soanellidae family (Saltite and Acoitella gen nov.). An ostracod shell bed is described and interpreted to be a parautochthonous assemblage, as a result of transport within the same habitat. The composition of the fauna, with the presence of Saltite and Nanopsis, shows significant affinities with East Gondwana. Copyright © 2011 John Wiley & Sons, Ltd.