New taxa of the superorder Spirillinoida (Foraminifera)

A new recent foraminiferal genus, Raskiniella gen. nov., with the type species Spirillina plana Wiesner, 1931, belonging to the family Raskiniellidae fam. nov., order Raskiniellida ord. nov. (subclass Spirillinana: superorder Spirillinoida), is described based on samples from Antarctica. The new genus is characterised by a complex canal system that has not been previously described in any other subclasses of multichamber foraminifera with a canal system. Canals extend inside the shell wall and are partly visible as a network on the wide peripheral margin of the shell. On the dorsal surface, these canals are radially arranged, resembling ribs, and extend perpendicularly to the chamber volutions towards the centre but do not reach it. A unique feature of the described canal system is the presence of smaller canals within larger ones; sometimes internal canals can be of third or even fourth order. The majority of the canals are located within the wall of the tubular chamber, forming a network of irregularly branching tubes that frequently intertwine, varying in shapes and sizes, often with swellings. It is the collective mass of these canals that constructs the framework of the shell. The round openings with a slightly projecting outer margin, located on the ventral side of the shall, previously described as pores in S. plana, are actually the external openings of the canal system and function as additional apertures. Since the type species of Spirillina Ehrenberg, 1843, S. vivipara Ehrenberg, 1843, like apparently all other or most species of the genus, does not possess a canal system, S. plana is transferred to the new genus, which is placed in the subclass Spirillinana.