Cainozoic and Recent deep sea cytherurid Ostracoda from south-west Pacific and eastern Indian Oceans: Part 1: Cytherurinae

Abstract

From a largely unpublished database the systematics, geographical and stratigraphical distribution of Cainozoic cytherurine Ostracoda found in the deep sea environment of the eastern Indiall and south-western Pacific regions is presented. Eleven new species: ? Eucytherura anoda, Eucytherura batalaria, ? Eucytherura boomeri, Eucytherura elegantula, Eucytherura indianensis, Eucytherura multi tubercula ta, Eucytherura pacifica, Eucytherura parabatalaria, ? Eucytherura polydictyota, Eucytherura tumida and Hemiparacytheridea vanharteni are described. Five species are assigrwd lo previously established taxa and four species are left in open nomenclature due to paucity of material. MICHAEL A. AYRESS, ROBIN WHATLEY, SIAN E. DOWNING & KARIN J. MILLSON, 1995. Cainozoic and Recent deep sea cytherurid Ostracoda from the south western Pacific and eastern Indian Oceans, Part I: Cytherurinae. Records of the Australian Museum 47(2): 203-223. Deep sea ostracod studies which have examined the fine fraction (less than 250 micron aperture seive) of samples frequently report species of the Cytheruridae. That this family comprises very small species (less than 0.40 mm in length) explains why they are poorly represented in most published faunal lists of deep sea ostracods. This study indicates that the group is well represented in the deep-sea at least in the Indo-Pacific region and that this has been so throughout the Cainozoic. The present study is concerned with the Cytherurinae. A subsequent paper will describe the Cytheropterinae. Taxonomic knowledge of deep sea forms of the genera considered in this report, is based on material collected mainly from the Atlantic region (Maddocks & Steineck, 1987; Whatley & Coles, 1987; Coles & Whatley, 1989). Material collected from the deep IndoPacific and compiled through comprehensive studies undertaken in the Micropalaeontological Research Unit, Aberystwyth, Wales, is still incorporated in largely unpublished theses. To assimilate the nomenclature contained therein with the present taxonomic study it is considered useful to list all names-unpublished as well as published-that have been applied to these taxa during the course of our work. (Unpublished references are indicated by asterisk *). This valuable source of information, useful for improving our understanding of the systematics and zoogeography of the taxa, is the focus of this report.