Nannotax Enabling nannofossil research

Remarks: Throughout the Neogene, discoasters can be found with blunt ray terminations, but otherwise similar morphology to co-occurring well-formed discoasters. The blunt ray-tip specimens have probably been produced both by diagenetic alteration and by original growth variation. Various species have been described to include these specimens including:

• D. aster Bramlette and Riedel, 1954;
• D. adamanteus Bramlette and Wilcoxon, 1967;
• D. argutus Hay, in HAY et al 1967
• D. lautus Hay, in HAY et al 1967
• D. obtusus Gartner 1967
• D. stellulus Gartner 1967
• D. rufus Roth 1970
• D. formosus Martini & Worsley
• D. intercalaris Bukry, 1971;
• D. toralus Ellis et al., 1972;
• D. chambrayensis Hojjatzadeh, 1978;
• D. zammitmaempeli Hojjatzadeh, 1978;
• D. toralus Ellis et al 1972
• D. capricornensis Rade 1977
• D. gillii Rade 1977

These species have no real value and it is more sensible to assign these specimens to an explicit category such as “unidentifiable 6-rayed discoaster”.

NB Of these D. adamanteus is a relatively widely used name, appied to short rayed discoasters which have been heavily overgrown so that they show crystallogaphic calcite faces on most surfaces.