Tenebrislaminam aequiscutum

Cyclococcolithus aequiscutum Gartner, 1967

Tremalithus rotula Kamptner, 1948, Invalid ICN Art. 35.1

Cyclicoccolithus rotula (Kamptner, 1948) Kamptner, 1956, Invalid ICN Art. 35.1

Cyclococcolithus cricotus Gartner, 1967

Geminilithella rotula (Kamptner, 1948) Backman, 1980, Invalid ICN Art. 35.1

Umbilicosphaera rotula (Kamptner, 1948) Varol, 1982, Invalid ICN Art. 35.1

Small (<7.0µm), circular species of Tenebrislaminam Varol, in prep. have a wide central area surrounded by narrow beaded segments and equal diameter single-cycled shields. The tube cycle is indistinct. The shields are non-birefringent, but beaded segments are very weakly birefringent. The distal shield is made up of strongly imbricated segments (sutures display left-handed inclination), whereas the proximal shield consists of non-imbricated segments with almost radial sutures. The segments of the proximal shield and the distal shield are thickened around the central opening.

Tenebrislaminam eaquiscutum is distinguished from Tenebrislaminam lordii (Varol, 1982) Varol, n. comb. by being smaller than 7.0µm. It differs from Tenebrislaminam jafarii (Müller) Varol, n. comb. by its larger size and having a larger central opening.

Backman, J., (1980): Miocene-Pliocene nannofossils and sedimentation rates in the Hatton-Rockall Basin, NE Atlantic Ocean. - Stockholm Contributions in Geology. 36: 1-91.

Gartner, S., (1967): Calcareous nannofossils from Neogene of Trinidad, Jamaica, and Gulf of Mexico. - University of Kansas Paleontological Contributions, Papers. 29: 1-7.

Kamptner, E., (1948): Coccolithen aus dem Torton des Inneralpinen Wiener Beckens. - Anzeiger der Österreichische Akademie der Wissenschaften, Mathematische-Naturwissenschafliche Klasse, Wien. 157: 1-16.

Müller, C., (1974): Nannoplankton aus dem Mittel-Miozän von Walbersdorf (Burgenland). - Senckenbergiana Lethaea. 55: 389-405.

Varol, O., (1982): Calcareous nannofossils from the Antalya Basin, Turkey. - Neues Jahrbuch für Geologie und Paläontologie, Monatshefte. 4: 244-256.