INTERNAL ARCHITECTURE OF MIOCENE PSEUDOTABERINA AND ITS RELATION TO CARIBBEAN ARCHAIASINS

Abstract:  Well-preserved, isolated specimens of Pseudotaberina were found at three localities in Indonesia, thus enabling the study of the relationships between this genus and Caribbean Archaiasinae. The internal architecture of the chambers of Pseudotaberina consists of four layers of stolon planes, each of which is divided by superposed septula into chamberlets. The chamberlets are connected to the next chambers by foramina opposing the septula. The stolons are Y-shaped. All other Archaiasinae have radial stolon axes combined with an initial involute growth stage, whereas the Soritinae have cross-wise oblique stolon axes, but with evolute growth in the early stages. Pseudotaberina shows a combination of the characters of these two subfamilies, confirming the need to study more Tethyan material to elucidate phylogenetic relationships within this group of large benthic foraminifera.