Structure and comparative anatomy of the toothplate in the Buliminacea (Foraminiferida)

Abstract. The toothplate is an important element of the apertural complex in the Buliminacea. Structurally speaking, it is a plate of inner lining, drawn out from under the apertural wall which descends into the lumen to contact the foramen. All the other apertural elements are bilamellar.

The degree of morphological complexity of the toothplate varies with the taxon; this has consequences for the taxonomy of the group. The diversity of the toothplate morphology in Bulimina might be used to divide the genus. Buliminella has to be revised since it seems to contain at least three separate entities, one of which does not belong to the Buliminacea. Praeglobobulimina is distinct from Globobulimina, the latter having lost the toothplate. Buliminellita and Turrilina are close relatives of Buliminella. Buliminoides has to be removed from the Buliminacea, and should be considered incertae familiae. Praebulimina possesses the simplest toothplate of the taxa investigated.