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Four new species of the ostracod genus Neosinocythere are described from the Indo-West Pacific region: N. indica, N. macropunctata, N. micropunctata and N. indowestpacifica. The diagnoses of Neosinocythere and the subfamily Sinocytherinae Huang are emended.

The endemic genus Sanyuania, one of the most important elements of the Cainozoic brackish water faunas unique to China, is redescribed, and 3 new species, S. wangi, S. cuneata and S. sublaevis are established, based on Quaternary material from the eastern coast of China. The evolution of the genus is discussed and a general trend involving a reduction in the strength of carapace ornamentation with time is established, as is a general migration seawards exhibited by subsequent chronological species.

This paper is a revision of Brady’s 1869 study of the Ostracoda of Hong Kong in ‘Les Fonds de la Mer’. In this he described the following nine new species: Cyrherella cingulata, Bairdia elegans, Bythocythere orientalis, Loxoconcha sinensis, L. hastata, Cytheridea impressa, Cythere cymba, C. euplectella and C. salebrosa. A detailed reappraisal of Brady’s original material which is deposited in the Hancock Museum, Newcastle-upon-Tyne, UK, and the Centre d’Etudes et de Recherches Scientifiques, Biarritz, France has revealed that the specimens of L. hastata are apparently lost. Holotypes and lectotypes have been designated by the authors for the other eight species. Those species which were subsequently recorded by Brady (1880) in the Challenger Report, such as C. cingulata, B. orientalis, L. sinensis and C. euplectella are demonstrated not to be conspecific with their original types first described in 1869. The following 10 species, Bythoceratina virgatella Hu, 1983 and B. cassidoidea Zhao, 1985; Cyprideis yehi Hu & Yeh, 1978, Sinocytheridea sinensis Hou. 1978, S. latiovata Hou & Chen, 1982, 5. lotjga Hou & Chen, 1982 and Eucytheridea sinobesani Hu, 1984: Cythereis subconvexa Kajiyama, 1913 and Aurila miii Ishizaki, 1968: Cythereis assimilis Kajiyama. 1913 are placed by the authors in the synonymies of Brady’s B. orientalis, C. impressa, C. cymba and C. salebrosa respectively.

Combined data of physical property, benthic foraminifera, and stable isotopes from ODP Sites 1148, 1146, and 1143 are used to discuss deep water evolution in the South China Sea (SCS) since the Early Miocene. The results indicate that 3 lithostratigraphic units, respectively corresponding to 21-17 Ma, 15-10 Ma, and 10-5 Ma with positive red parameter (a*) marking the red brown sediment color represent 3 periods of deep water ventilation. The first 2 periods show a closer link to contemporary production of the Antarctic Bottom Water (AABW) and Northern Component Water (NCW), indicating a free connection of deep waters between the SCS and the open ocean before 10 Ma. After 10 Ma, red parameter dropped but stayed higher than the modern value (a*=0), the CaCO3 percentage difference between Site 1148 from a lower deepwater setting and Site 1146 from an upper deepwater setting enlarged significantly, and benthic species which prefer oxygen-rich bottom conditions dramatically decreased. Coupled with a major negative excursion of benthic delta(13) C at similar to 10 Ma, these parameters may denote a weakening in the control of the SCS deep water by the open ocean. Probably they mark the birth of a local deep water due to shallow waterways or rise of sill depths during the course of sea basin closing from south to east by the west-moving Philippine Are after the end of SCS seafloor spreading at 16-15 Ma. However, it took another 5 Ma before the dissolved oxygen approached close to the modern level. Although the oxygen level continued to stabilize, several Pacific Bottom Water (PBW) and Pacific Deep Water (PDW) marker species rapidly increased since similar to 6 Ma, followed by a dramatic escalation in planktonic fragmentation which indicates high dissolution especially after similar to 5 Ma. The period of 5-3 Ma saw the strongest stratified deepwater in the then SCS, as indicated by up to 40% CaCO3 difference between Sites 1148 and 1146. Apart from a strengthening PDW as a result of global cooling and ice cap buildup on northern high latitudes, a deepening sea basin due to stronger subduction eastward may also have triggered the influx of more corrosive waters from the deep western Pacific. Since 3 Ma, the evolution of the SCS deep water entered a modern phase, as characterized by relative stable 10% CaCO3 difference between the two sites and increase in infaunal benthic species which prefer a low oxygenated environment. The subsequent reduction of PBW and PDW marker species at about 1.2 Ma and 0.9 Ma and another significant negative excursion of benthic delta C-13 to a Neogene minimum at similar to 0.9 Ma together convey a clear message that the PBW largely disappeared and the PDW considerably weakened in the Mid-Pleistocene SCS. Therefore, the true modern mode SCS deep water started to form only during the "Mid-Pleistocene climatic transition" probably due to the rise of sill depths under the Bashi Strait.

Based on the stable isotopic analysis of more than 1000 samples of planktonic and benthic foraminifers from ODP Site 1148 in the northern South China Sea (SCS), the oxygen isotope stratigraphy has been applied to the last 3 million years for the first time in the SCS. Furthermore, the paleoceanographic changes in the northern SCS during the last 6 million years have been unraveled. The benthic foraminiferal δ 18 O record shows that before ~3.1 Ma the SCS was much more influenced by the warm intermediate water of the Pacific. The remarkable decrease in the deepwater temperature of the SCS during the period of 3.1—2.5 Ma demonstrates the formation of the Northern Hemisphere ice-sheet. However, the several sea surface temperature (SST) reductions during the early and middle Pliocene, reflected by the planktonic foraminiferal δ 18 O, might be related to the ice-sheet growth in the Antarctic region. Only those stepwise and irreversible SST reductions during the period of ~2.2—0.9 Ma could be related to the formation and growth of the Northern Hemisphere ice-sheet.