Nannotax Enabling nannofossil research

Description: Coccosphere dimorphic; coccoliths consist of a funnel-shaped distal part on a flat base. The funnel elements are continuous with the basal plate elements of the central area; a flange may be present around the basal plate, formed by a separate cycle of elements. Coccoliths are variable in size.

Type genus and species: Umbellosphaera tenuis.

Remarks: Kleijne (1993) described a sub-family, the Umbellosphaeroideae, within the Syracosphaeraceae, including Umbellosphaera and Gaarderia. With higher resolution SEM observations and better understanding of Syracosphaera coccolith morphology it became clear that Gaarderia corolla should be recombined into Syracosphaera, but that Umbellosphaera is not associated with the Syracosphaerales. For consistency of taxonomic usage, Young et al. (2003) raised the taxon Umbellosphaeroideae from sub-family to family status.The family is tentatively placed in the Coccolithlaes here on the basis of molcular gentic data (Hui & de Vargas pers. comm.)