THE GENUS ANGULOGAVELINELLA HOFKER, 1957, AND ITS SPECIES (FORAMINIFERIDA, ROTALIINA UPPER CRETACEOUS LOWER TERTIARY)

The old world genus Angulogavelinella Hofker, 1957, is newly described , detailing apertural characteristics, functional morphology, ultrastr ucture, and test variability, Apertures and foramina are divided by a bridge into primary and umbilical parts (aperture/foramen and foliar a perture), Folia cover open canals in which protoplasm could flow from large openings (with direct access to the inner whorls) into the umbil icus and vice versa, In specimens with an umbilical boss, an open ring canal was formed and covered by cantilever folia, Thus Angulogaveline lla is just below the true rotaliids in systematics and functional mor phology. The ultrastructure of the wall is bilamellar, and the septa a re bilamellar with a septal flap, Well preserved specimens exhibit a h erringbone arrangement of calcite platelets and remnants of pore plate s and pore plugs, so far known from other genera only in Recent to upp er Miocene material. A phylogenetic lineage of seven species ranging f rom the Santonian to the upper Paleocene is presented, Gavelinella ste lligera (Marie) is the proposed ancestor. Two new species, A. ahuvae a nd A. angustiumbilicata, are described, A neotype is established for A , gracilis (Marsson).