Daughter taxa (time control age-window is: 0-800Ma)
Ophiaster macrospinus Like O. formosus but CFCs with broader process and link coccoliths wide, sub-rectangular, with only a single small spike.
Ophiaster formosus BCs with central plaque formed of a few laths. Link coccoliths short and broad
Ophiaster hydroideus Similar to O. formosus but with more elongate link coccoliths.
Ophiaster reductus BCs - with laths but no axial structure. Cycle of small antapical BCs with open central area surrounds whorl; link coccoliths often with single spine
Ophiaster minimus Very small (coccosphere ca. 3.5 µm). BCs simple rings, without central structures. Proximal link liths distinctive, diamond shaped with diagonal bar. CFCs with short spine supported by axial cross
Ophiaster formosus var. inversus Variant of O. formosus with first link showing opposite taper to usual - i.e. narrow end attached to coccosphere. Specimens have not been illustrated since the original description and possibly these were artefacts.
Ophiaster sp. Specimens which cannot be assigned to established species
Bernardosphaera Lecal-Schlauder 1951 [the long arms formed of numerous osteoliths indicate the taxon illustrated by Lecal is Ophiaster]
Distinguishing features: Parent taxon (Syracosphaeraceae): BCs muroliths or placoliths with radial laths and axial structure, ofen with higlhy modified exothecal coccoliths This taxon: Appendages formed from strings of highly modified antapical coccoliths, without whorl coccoliths
BCs - elliptical weakly calcified muroliths; rim narrow with weak proximal flange.
CFCs - like BCs but with spines.
Antapical link coccoliths (osteoliths) - form a ring of usually 4-7 arms. Elongate with spoon-like and tongue-like ends. Slightly curved in plan view, rim elements short along concave side and longer on convex side, sometimes extended into thorn-like processes. First link is differentiated from the others, typically having broader end where it attaches to the coccosphere.
Arms can be either wrapped around the coccosphere or deployed radially. It is thought they form in wrapped-around position and that radial-deployment may be a defence mechansm, Young et al. (2009).
The morphological data given here can be used on the advanced search page. See also these notes
Geological Range: Last occurrence (top): Extant. Data source: Total of ranges of the species in this database First occurrence (base): within No known fossil record modern (0.00-0.00Ma, base in "Holocene" stage). Data source: Total of ranges of species in this database
Plot of occurrence data:
Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested
Gran, H. H. (1912). Pelagic plant life. In, Murray, J. & Hjort, J. (eds) The Depths of the Ocean. Macmillan, London 307-386. gs
Lecal-Schlauder, J. (1951). Recherches morphologiques et biologiques sur les Coccolithophorides Nord-Africains. Annales de l'Institut Océanographique, Monaco & Paris. 26: 255-362. gs
Young, J. R., Andruleit, H. & Probert, I. (2009). Coccolith function and morphogenesis, insights from appendage-bearing coccolithophores of the family Syracosphaeraceae (Haptophyta). Journal of Phycology. 45: 213-226. gs
Ophiaster compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 22-5-2025
These terms and conditions contain rules about posting comments. By submitting a comment, you are declaring that you agree with these rules:
Although the administrator will attempt to moderate comments, it is impossible for every comment to have been moderated at any given time.
You acknowledge that all comments express the views and opinions of the original author and not those of the administrator.
You agree not to post any material which is knowingly false, obscene, hateful, threatening, harassing or invasive of a person's privacy.
The administrator has the right to edit, move or remove any comment for any reason and without notice.
Failure to comply with these rules may result in being banned from submitting further comments.
These terms and conditions are subject to change at any time and without notice.
{"commentics_url":"\/\/www.mikrotax.org\/comments\/","page_id":786412,"enabled_country":true,"country_id":0,"enabled_state":false,"state_id":0,"enabled_upload":false,"maximum_upload_amount":3,"maximum_upload_size":5,"maximum_upload_total":5,"captcha":true,"captcha_url":"https:\/\/www.mikrotax.org\/comments\/frontend\/index.php?route=main\/form\/captcha&page_id=786412","cmtx_wait_for_comment":"cmtx_wait_for_comment","lang_error_file_num":"A maximum of %d files are allowed to be uploaded","lang_error_file_size":"Please upload files no bigger than %.1f MB in size","lang_error_file_total":"The total size of all files must be less than %.1f MB","lang_error_file_type":"Only image file types are allowed to be uploaded","lang_text_loading":"Loading ..","lang_placeholder_country":"Country","lang_placeholder_state":"State","lang_text_country_first":"Please select a country first","lang_button_submit":"Add Comment","lang_button_preview":"Preview","lang_button_remove":"Remove","lang_button_processing":"Please Wait.."}
Comments