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Tianjinella ovata
Tianjinella ovata (Jiabo, 1978, p.94, pl.6, fig.1) He Chengquan and Sun Xuekun, 1996, p.385.
Originally Dinogymnium ovatum, subsequently Microdinium jiaboense, thirdly (and now) Tianjinella ovata.
Holotype: Jiabo, 1978, pl.6, fig.1.
Age: Early Tertiary.
Basionym: Dinogymnium ovatum Song et al. 1978, p. 94, pl. 6, fig.1
Remarks: Based on an examination of the type material in China by Lentin in 1987, Lentin and Williams (1989, p. 245) transferred Dinogymnium ovatum to the genus Microdinium Cookson and Eisenack, 1960 as M. jiaboense. We reject this transfer because D. ovatum Song et al. lacks parasutural ridges, paracingular plates and has approximately equal-sized epitheca and hypotheca, which is quite different from the characteristic features of Microdinium. We included D. ovatum in Tianjinella He and Sun, gen. nov. as T. ovata (Song et al., 1978) He and Sun, comb. nov. since it accords with the new genus in having a small, rounded body, an apical archeopyle, bead-shaped intratabular processes and in lacking paracingular processes.
Originally Dinogymnium ovatum, subsequently Microdinium jiaboense, thirdly (and now) Tianjinella ovata.
Holotype: Jiabo, 1978, pl.6, fig.1.
Age: Early Tertiary.
Basionym: Dinogymnium ovatum Song et al. 1978, p. 94, pl. 6, fig.1
Remarks: Based on an examination of the type material in China by Lentin in 1987, Lentin and Williams (1989, p. 245) transferred Dinogymnium ovatum to the genus Microdinium Cookson and Eisenack, 1960 as M. jiaboense. We reject this transfer because D. ovatum Song et al. lacks parasutural ridges, paracingular plates and has approximately equal-sized epitheca and hypotheca, which is quite different from the characteristic features of Microdinium. We included D. ovatum in Tianjinella He and Sun, gen. nov. as T. ovata (Song et al., 1978) He and Sun, comb. nov. since it accords with the new genus in having a small, rounded body, an apical archeopyle, bead-shaped intratabular processes and in lacking paracingular processes.