Discoaster is a genus of extinct star-shaped marine algae, with calcareous exoskeletons of between 5-40μm across that are abundant as nanofossils in tropical deep-ocean deposits of Neogene age. Discoaster belongs to the haptophytes. About 100species can be recognized.

Biostratigraphic significance

The International Commission on Stratigraphy (ICS) has assigned the extinction of Discoaster brouweri as the defining biological marker for the start of the Calabrian Stage of the Pleistocene, 1.806million years ago. ICS has assigned the extinction of Discoaster pentaradiatus and Discoaster surculus as the defining biological marker for the start of the Gelasian Stage, 2.588million years ago, the earliest stage of the Pleistocene. ICS further assigned the extinction of Discoaster kugleri as biological marker for the start of the Tortonian Stage of the Miocene, 11.62million years ago.

Species

Some species in this genus include:

1. {|

|+ ! Species !! Authority |- | D.asymmetricus || |- | D.bellus || |- | D.berggrenii || |- | D.bollii || |- | D.brouweri || |- | D.calcaris || |- | D.exilis || |- | D.hamatus || |- | D.intercalaris || |- | D.kugleri || |- | D.loeblichii || |- | D.neohamatus || |- | D.neorectus || |- | D.pentaradiatus || |- | D.quintatus || |- | D.surculus || |- | D.toralus || |- | D.triradiatus || |- | D.variabilis || |- | D. arneyi || |- |}

References