The relative abundance of unilocular forms was not taken to perform factor analysis Trametinib chemical structure because their ecological preferences are not well known. Q-mode factor

analysis was performed on a reduced data set of the 51 highest ranked species (Table 1) at this site using a commercially distributed statistical package (SPSS 9.0) to establish the correlation between benthic foraminiferal assemblages and environmental conditions. This method involves principal component analysis followed by VARIMAX rotation. The benthic foraminiferal quantitative data were used to calculate Hurlbert’s diversity index, Sm (Hurlbert 1971). Hurlbert’s diversity index is defined by the function equation(1) Sm=∑i=1S1−CN−Ni,m/CNm, where Sm is the expected number of species in a random sub-sample of size m (m ≥ N). In the present study m = 100, which is well below the lowest number of specimens counted per sample. N is the number of specimens in the sample and S is the number of species in which N specimens are distributed. Ni is learn more the number of individuals in

the i-th species, ∑Ni=N. C(N − Ni, m) = (N − Ni)!/[m!(N − Ni − m)!] and C(N, m) = N!/[m!(N − M)!] for (N − Ni) ≥ m and N ≥ m respectively, and zero for (N − Ni) < m and N < m respectively (Smith & Grassle 1977). The percentages of shallow infaunal and other infaunal taxa were calculated following Wells et al. (1994), and the percentages of oxic and suboxic taxa were calculated following Kaiho (1994). We also compared the faunal diversity with some faunal abundance data. Benthic foraminifera were grouped into percentages

of total cylindrical elongate taxa (predominantly stilostomellids) following Hayward (2002) and Smart et al. (2007). High productivity taxa are explained as the sum of various infaunal taxa, i.e. Bulimina spp., Melonis spp., Uvigerina spp., Ehrenbergina spp., Eggerella bradyi, Sphaeroidina bulloides and Pullenia bulloides following Gooday, 1994 and Gooday, 2003 and Loubere (1996). The nannofossil datum levels, like those selected by Siesser et al. (1992), were used to construct the age model for Site 762B. But the Ureohydrolase numerical ages were reassigned according to the timescale of Berggren et al. (1995) and Lourens et al. (2004) (Figure 2). Our age model for this site is thus the same as that in Siesser et al. (1992) in their interpretation of the biomagnetostratigraphy, with differences only in the update of the numerical ages of datum levels (Table 2). Pliocene-Pleistocene deep sea benthic foraminifera show major fluctuations and long-term changes at ODP Site 762B (Figure 3 and Figure 4). The most abundant species include Uvigerina proboscidea, Cibicides lobatulus, Cibicides wuellerstorfi, Bulimina aculeata, Bulimina alazanensis, Stilostomella lepidula, Oridorsalis umbonatus and Gyroidinoides cibaoensis.