NEW SPECIES OF THE GENUS PARKIELLA (FORAMINIFERA) FROM THE LATE CRETACEOUS CENTRAL PACIFIC-OCEAN - BIOSTRATIGRAPHY, BIOGEOGRAPHY, AND THE CRETACEOUS-PALEOGENE BOUNDARY

Two new species, Parkiella angulocamerata sp. nov. and P. globocamerat a sp. nov., are described from the Late Cretaceous (late Maastrichtian ) Central Pacific Ocean, DSDP Sites 465 and 171. Examination under the SEM revealed apertural features that were not documented in the origi nal description of Parkiella. An 'L'-shaped aperture was originally co nsidered as a diagnostic character of Parkiella; we suggest that this is a preservational artefact and question its diagnostic value. The ex istence of internal toothplates determine both Parkiella described her e as members of the family Turrilinidae Cushman 1927. Both species wer e found to be endemic to the tropical Pacific Ocean. They occurred in sequence throughout the Maastrichtian section at Site 465 with a minim um (one sample) stratigraphic overlap. Parkiella globocamerata is one of the few deep-sea benthic foraminiferal species that indeed became e xtinct at the Cretaceous/Palaeogene (K/Pg) boundary. However, we docum ent a decrease in both relative abundance and accumulation rate of the species already prior to the K/Pg transition. We propose that the int erval between the LO (Last Occurrence) of P. angulocamerata ara and th e LO of P. globocamerata nra is indicative of uppermost Cretaceous (Mi cula prinsii Zone) strata in the tropical Pacific.