Aktasia disgregatus

Discolithus disgregatus Stover, 1966

Eiffellithus testaceus Reinhardt, 1966

Zygolithus cuneatus Lyul'eva, 1967

Large species of Aktasia (> 6.0 µm) have a zeugoid outer wall and a protolith inner wall composed of eight large sub-quadrilateral segments. The central area contains a symmetrical diagonal cross whose arms are composed of parallel longitudinal segments arranged in two halves and lacking a distal process.

Aktasia disgregatus is identified from Aktasia trabeculatus by being greater than 6.0 µm.

Aktasia disgregatus differs from Aktasia irregularis by having a symmetrical cross, whereas the latter has an asymmetrical cross.

The highest abundance of Aktasia disgregatus was recorded at 85.5 Ma.

Cepek, P. & Hay, W.W. 1970. Zonation of the Upper Cretaceous using calcareous Nannoplankton. Palaont. Abh. Abt. B Palaobotanik. 3(3/4): 333-340.

Górka, H. 1957. Les Coccolithophoridés du Maestrichtien supérieur de Pologne. Acta Palaeontologica Polonica. 2: 239-284

Lyul'eva, S.A. 1967. Coccolithophoridae in the Turonian strata of the Dneiper-Don Basins. Geologische Zhurnal. 27: 91-98

Reinhardt, P. 1965. Neue Familien für fossile Kalkflagellaten (Coccolithophoriden, Coccolithineen). Monatsberichte der Deutschen Akademie der Wissenschaften zu Berlin. 7: 30-40.

Reinhardt, P. 1966b. Zur Taxonomie und Biostratigraphie des fossilen Nannoplanktons aus dem Malm, der Kreide und dem Alttertiär Mitteleuropas Freiberger Forschungshefte. C196: 5-109.

Stover, L. E. 1966. Cretaceous coccoliths and associated nannofossils from France and the Netherlands. Micropaleontology 12(2): 133-167.

Varol, O. & Girgis, M. 1994. New taxa and taxonomy of some Jurassic to Cretaceous calcareous nannofossils. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen. 192: 221-253.