Multipartis ponticus Varol 1989c
From Greek perideraio, necklace and lithos, stone – refers to its pearl necklace-like appearance.
Holococcoliths with a two-crystalline high wall and a multi-block central structure featuring a low distal process. Each storey of the wall consists of more than twelve relatively large crystalline units (approximately 1.0–1.50 μm). The proximal wall resembles a beaded necklace in the side view at a 45 ° angle. The holococcolith exhibits an elliptical outline in the plan view, with numerous crystals in the central area supporting a low distal process, which is best observed in the side view.
In the plan view, the wall displays inclined extinction lines at an angle of about 7 °, indicative of a rhombohedral crystal structure, with length-slow (+) elongation. In the side view, the distal wall exhibits length-fast (–) elongation, while the proximal wall and the distal process show length-slow (+) elongation.
Perideraiolithos differs from Diorofostoichos by having more than twelve crystalline units in each storey and a multi-crystalline central structure with a distal process. In contrast, Diorofostoichos has fewer than twelve crystalline units per storey and lacks a distal process. Additionally, in the plan view, Diorofostoichos typically has a single disjunct crystalline unit in the central area, whereas Perideraiolithos contains numerous crystalline units in the central area.
Varol, O. 1989c. Palaeocene calcareous nannofossil biostratigraphy. In: Crux, J. A. & van Heck, S. E. (Eds), Nannofossils and their applications. Proceedings of the 2nd INA Conference, London 1987. British Micropalaeontological Society Publication Series 265-310.
Varol, O. 2025b. New observation on Paleocene holococcoliths. Neues Jahrbuch für Geologie und Paläontologie,