Blackites tenuis

(Bramlette & Sullivan, 1961) Sherwood, 1974 Apr 26, 2021

Set number: 1115

  • Blackites tenuis VR 02915 1
  • Blackites tenuis VR 02912 2
  • Blackites tenuis VR 02919 3
  • Blackites tenuis VR 02923 4
  • Blackites tenuis VR 02917 5
  • Blackites tenuis VR 02913 6
  • Blackites tenuis VR 02918 7
  • Blackites tenuis VR 02924 8
  • Blackites tenuis VR 02916 9
  • Blackites tenuis VR 02914 10
  • Blackites tenuis VR 02922 11
  • Blackites tenuis VR 02925 12
    10µm
Blackites tenuis, Middle Eocene, DSDP Leg 39, Sites 356, Sào Paulo Plateau, South Atlantic Ocean

Set number: 1114

  • Blackites tenuis VR 02681 1
  • Blackites tenuis VR 02680 2
  • Blackites tenuis VR 02684 3
  • Blackites tenuis VR 02688 4
  • Blackites tenuis VR 02682 5
  • Blackites tenuis VR 02679 6
  • Blackites tenuis VR 02683 7
  • Blackites tenuis VR 02687 8
    10µm
Blackites tenuis, Middle Eocene, DSDP Leg 39, Sites 356, Sào Paulo Plateau, South Atlantic Ocean
Final Epithet
Blackites tenuis (Bramlette & Sullivan, 1961) Sherwood, 1974
Basionym

Rhabdosphaera tenuis Bramlette & Sullivan, 1961

Description

Species of Blackites Hay & Towe (1962) have a long and asymmetrical distal process that gradually tapers to a point. The inner cycles of the base are birefringent at the side view. The surface of the distal process is smooth. The maximum diameter of the distal process is about half that of the base.

The symmetrical forms were also erroneously assigned to Blackites tenuis in the publications.

Remarks

Blackites tenuis is identified from Blackites incompertus Roth (1970) by having an asymmetrical distal process that gradually tapers to a point whereas, in the latter species, the distal process slightly broadens in the middle.

References

Bramlette, M. N. & Sullivan, F. R., (1961): Coccolithophorids and related nannoplankton of the Early Tertiary in California. - Micropaleontology. 7(2): 129-188.

Deflandre, G. & Fert, C., (1954): Observations sur les coccolithophoridés actuels et fossiles en microscopie ordinaire et électronique. - Annales de Paléontologie. 40: 115-176.

Hay, W. W. & Towe, K. M., (1962): Electron microscope examination of some coccoliths from Donzacq (France). - Eclogae Geologicae Helvetiae. 55: 497-517.

Roth, P. H., (1970): Oligocene calcareous nannoplankton biostratigraphy. - Eclogae Geologicae Helvetiae. 63: 799-881.

Sherwood, R. W., (1974): Calcareous nannofossil systematics, palaeoecology and biostratigraphy of the Middle Eocene Weches Formation of Texas. - Tulane Studies in Geology. 11: 1-79

Taxonomy
Blackites
Biostratigraphy
  • Phanerozoic
    • Cenozoic
      • Paleogene
        • Oligocene
          • Middle Oligocene
            • Rupelian
        • Eocene
          • Middle Eocene
            • Lutetian
Stratigraphic Range
Lutetian - Rupelian
Age (Ma)
48.07? - 31.00
Holotype
Blackites tenuis VR 02912

Rhabdosphaera tenuis Bramlette & Sullivan, 1961

Middle Eocene

Lodo section, northwestern Fresno County, central California, USA