New species of the genus &amp;lt;i&amp;gt;Parkiella&amp;lt;/i&amp;gt; (Foraminifera) from the Late Cretaceous Central Pacific Ocean: biostratigraphy, biogeography, and the Cretaceous–Palaeogene boundary

Joen G V Widmark,Michal Kucera

doi:10.1144/jm.17.1.51

Abstract

Abstract. Two new species, Parkiella angulocamerata sp. nov. and P. globocamerata 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 original description of Parkiella. An ‘L’-shaped aperture was originally considered as a diagnostic character of Parkiella; we suggest that this is a preservational artefact and question its diagnostic value. The existence of internal toothplates determine both Parkiella described here as members of the family Turrilinidae Cushman 1927. Both species were found to be endemic to the tropical Pacific Ocean. They occurred in sequence throughout the Maastrichtian section at Site 465 with a minimum (one sample) stratigraphic overlap. Parkiella globocamerata is one of the few deep-sea benthic foraminiferal species that indeed became extinct at the Cretaceous/Palaeogene (K/Pg) boundary. However, we document a decrease in both relative abundance and accumulation rate of the species already prior to the K/Pg transition. We propose that the interval between the LO (Last Occurrence) of P. angulocamerata and the LO of P. globocamerata is indicative of uppermost Cretaceous (Micula prinsii Zone) strata in the tropical Pacific.

Highlights

The benthic foraminiferal fauna from the uppermost Cretaceous and lowermost Palaeogene strata at Site 465 has not yet been described in detail - apart from the documentation of the most common taxa by Widmark & Malmgren (1992a, b) and short communication by Widmark & Henriksson (1995)
In this paper we describe two new species typical for this fauna, discuss their taxonomic position, biostratigraphic significance, and biogeographic distribution
During a study on benthic foraminiferal changes across the Cretaceous/Palaeogene (K/Pg) boundary at three DSDP sites, one from the Pacific Ocean (Site 465) and two from the South Atlantic Ocean (Sites 525 and 527), Widmark & Malmgren (1992a) encountered several taxa that had not been previously described in the literature

Summary

INTRODUCTION

The benthic foraminiferal fauna from the uppermost Cretaceous and lowermost Palaeogene strata at Site 465 (and from the Late Cretaceous of the Central Pacific Ocean in general) has not yet been described in detail - apart from the documentation of the most common taxa by Widmark & Malmgren (1992a, b) and short communication by Widmark & Henriksson (1995). During a study on benthic foraminiferal changes across the Cretaceous/Palaeogene (K/Pg) boundary at three DSDP sites, one from the Pacific Ocean (Site 465) and two from the South Atlantic Ocean (Sites 525 and 527), Widmark & Malmgren (1992a) encountered several taxa that had not been previously described in the literature. Among these was a ‘buliminid’ species from Site 465, tentatively named Buliminella? We present a detailed account on its response to the K/Pg boundary event in terms of both relative abundances and accumulation rates

MATERIAL AND METHODS

Findings

Site465