Previous   |    Next

doi:10.2204/iodp.proc.303306.211.2010

Taxonomy of Gephyrocapsids

Most of the species identified in this study belong to the family Noelaerhabdaceae (reticulofenestrids including the genera Emiliania, Pseudoemiliania, Reticulofenestra, and Gephyrocapsa) (Thierstein et al., 1977; Raffi et al., 1993; Wei, 1993; Flores et al., 1999; Flores et al., 2000). Gephyrocapsid taxonomy is based on reports by Raffi et al. (1993), Flores et al. (2000), Takahashi and Okada (2000), and Baumann and Freitag (2004). The genus Gephyrocapsa was first divided into Gephyrocapsa caribbeanica, Gephyrocapsa oceanica, Gephyrocapsa muellerae, and other forms, and the latter were divided into two taxonomic groups based on coccolith length (i.e., small [2.5–3.5 µm] and very small [<2.5 µm]). Several authors found that the angle between the lob axis and the bridge of Gephyrocapsa was related to temperature (e.g., Bollmann, 1997). We also classified very small Gephyrocapsa spp. into three groups: >45° (Gephyrocapsa spp. [small] and G. oceanica), 0°–25° (G. muellerae), and 0°–45° (G. caribbeanica), which indicate warm, cold, and intermediate temperature, respectively. In particular, the very small forms of Gephyrocapsa spp. and Reticulofenestra spp. are mainly represented by specimens smaller than 2.5 µm (Table T1).

Top of page   |    Previous   |    Next