<i>Discoaster surculus</i> - Tertiary fossil skeleton of nannoplankton; from a sample of a marine  sediment core
<a href="//commons.wikimedia.org/wiki/User:Hgrobe" title="User:Hgrobe">Hannes Grobe</a> 20:47, 12 November 2006 (UTC), Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany
CC BY 2.5
own work; SEM foto, Geological Institute, Kiel