Aktasia compacta

Vagalapilla compacta compacta Bukry, 1969

Placozygus latidecussatus Hoffmann, 1970

Helicolithus compactus (Bukry, 1969) Varol & Girgis, 1994

Maximum size: 5.50 µm

Small species of Aktasia (<6.0 µm) characterised by a zeugoid outer wall and a protolith inner wall composed of eight large, sub-quadrilateral segments. The central area is traversed by an asymmetrical diagonal cross lacking a distal process; its arms consist of parallel longitudinal segments arranged in two halves.

Aktasia compacta is identified from Aktasia irregularis by being smaller than 6.0 µm.

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

Bukry, D. 1969. Upper Cretaceous coccoliths from Texas and Europe. University of Kansas Paleontological Contributions, Articles 51 (Protista 2): 1-79.

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.