{{Short description|Extinct genus of single-celled organisms}} {{Automatic taxobox | fossil_range = {{fossil range |Paleocene |Pleistocene |ref=<ref name=Bukry-1971> {{cite journal | last = Bukry | first = David | year = 1971 | title = Discoaster evolutionary trends | journal = Micropaleontology | volume = 17 | pages = 43–52 | issue = 1 | publisher = The Micropaleontology Project, Inc. | jstor = 1485036 | doi = 10.2307/1485036 }}</ref> |ps=Most abundant during Miocene }} | image = Discoaster surculus 01.jpg | image_caption = ''Discoaster surculus'', about 15 μm across | taxon = Discoaster | authority = S.H. Tan, 1931 }} {{commons category|Discoaster}}
'''''Discoaster''''' is a genus of extinct star-shaped marine algae, with calcareous exoskeletons of between 5-40 μm across that are abundant as nanofossils in tropical deep-ocean deposits of Neogene age. ''Discoaster'' belongs to the haptophytes. About 100 species can be recognized.<ref name=SpringerRef> {{cite web |title=Discoasters |website=Springer Reference |publisher=Springer |url=http://www.springerreference.com/docs/html/chapterdbid/43485.html |access-date=4 July 2013 }}</ref>
== 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, 1.806 million 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, 2.588 million 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, 11.62 million years ago.
== Species == Some species in this genus include:<ref name=SpringerRef/><ref name=Raffi-etal-2003> {{cite journal |last1=Raffi |first1=I. |last2=Mozzato |first2=C. |last3=Fornaciari |first3=E. |last4=Hilgen |first4=F.J. |last5=Rio |first5=D. |date=Spring 2003 |title=Late Miocene calcareous nannofossil biostratigraphy and astrobiochronology for the Mediterranean region |journal=Micropaleontology |volume=49 |issue=1 |pages=1–26 |doi=10.1661/0026-2803(2003)049[0001:LMCNBA]2.0.CO;2 <!--|accessdate=01-07-2009--> |publisher=The Micropaleontology Project, Inc. |s2cid=198157383 }} </ref><ref name=AlgaeDB> {{cite web |last1=Guiry |first1=M.D. |last2=Guiry |first2=G.M. |year=2008 |title=Discoaster |website=AlgaeBase |department=World-wide electronic publication |publisher=National University of Ireland |place=Galway, IE |url=http://www.algaebase.org/search/genus/detail/?genus_id=45430 |access-date=2009-02-21 }} </ref> :{| |+ {{big|''Discoaster''}} ! Species !! Authority |- | ''D. asymmetricus'' || {{small|Gartner}} |- | ''D. bellus'' || {{small|Bukry & Percival}} |- | ''D. berggrenii'' || {{small|Bukry}} |- | ''D. bollii'' || {{small|Martini & Bramlette}} |- | ''D. brouweri'' || {{small|Bramlette & Riedel}} |- | ''D. calcaris'' || {{small|Gartner}} |- | ''D. exilis'' || {{small|Martini & Bramlette}} |- | ''D. hamatus'' || {{small|Martini & Bramlette}} |- | ''D. intercalaris'' || {{small|Bukry}} |- | ''D. kugleri'' || {{small|Martini & Bramlette (1963)}} |- | ''D. loeblichii'' || {{small|Bukry}} |- | ''D. neohamatus'' || {{small|Bukry & Bramlette}} |- | ''D. neorectus'' || {{small|Bukry}} |- | ''D. pentaradiatus'' || {{small|(Tan, 1931) Bramlette & Riedel}} |- | ''D. quintatus'' || {{small|Gartner}} |- | ''D. surculus'' || {{small|Martini & Bramlette}} |- | ''D. toralus'' || {{small|Ellis, Lohmann, & Wray}} |- | ''D. triradiatus'' || {{small|Tan (1931)}} |- | ''D. variabilis'' || {{small|Martini & Bramlette}} |- | ''D. arneyi'' || {{center|—}} |- |}
== References == {{Reflist|25em}}
{{Taxonbar|from=Q5281570}}
Category:Haptophyte genera Category:Prehistoric eukaryote genera Category:Index fossils Category:Paleocene first appearances Category:Pleistocene genus extinctions
{{Haptophyte-stub}}