• Globigerina tripartita Koch.—Blow and Banner, 1962:96 (partim), pl. 10, figs. D-F [upper Eocene Cribrohantkenina danvillensis Zone, Lindi area, Tanzania].—Blow, 1969:322, pl. 16, fig. 6 [upper Eocene Zone P15, Lindi area, Tanzania].—Stainforth and others, 1975:325, 328 (partim), fig. 148, nos. 1, 6 [upper Eocene Globigerinatheka semi-involuta Zone, Navet Fm., Trinidad] (not fig. 148, nos 2-5, 7, 8 = Dentoglobigerina tripartita). [Not Koch, 1926.]
• Dentoglobigerina tripartita (Koch).—Blow, 1979:1310, pl. 244, figs. 3, 4 [upper Eocene Zone P16, Lindi area, Tanzania].—Olsson and others, 2006:408-410 (partim), pl. 13.3, figs. 4, 15 [upper Eocene Zone E16, Nanggulan Fm., Java], fig. 5 (reproduced from Blow, 1979, pl. 244, fig. 3), fig. 6 (reproduced from Blow, 1969, pl. 16, fig. 6), figs. 7, 8 [upper Eocene Zone E15/16, TDP Site 11, Tanzania], figs. 9-11 [upper Eocene Zone E15/E16, Shubuta Clay, Mississippi], fig. 14 [upper Eocene Zone E15, Istra More-4 well, Adriatic Sea] (Not pl. 13.3, figs. 1-3 = holotype; not pl. 13.3, figs. 12, 16 = Dentoglobigerina galavisi). [Not Koch, 1926.]
• Dentoglobigerina cf. tripartita (Koch).—Pearson and Wade, 2015:20, fig. 21.1 (reproduced from Blow, 1969, pl. 16, fig. 6), fig. 21.2 (reproduced from Blow, 1979, pl. 244, fig. 4), fig. 21.3a-b (reproduced from Olsson and others, 2006, pl. 13.3, figs. 7, 8), fig. 21.4a-7f [upper Eocene Zone E15/16, TDP Site 12, Tanzania] (Note fig. 21.4a-e = holotype designated here, NHMUK PM 71285; fig. 21.6a-b = paratype designated here, NHMUK PM 71286; fig. 21.7a-c = paratype designated here, NHMUK PM 71287).
• Dentoglobigerina pseudovenezuelana (Blow and Banner).—Olsson and others, 2006:404-408 (partim), pl. 13.2, figs. 9, 12 [upper Eocene Zone E15/16, Shubuta Clay, Wayne County, Mississippi]. [Not Blow and Banner, 1962.]

This species was initially identified in the Atlas of Eocene Planktonic Foraminifera (2006) as D. tripartita (Koch). At that time, an SEM of the tripartita holotype was unavailable and identification relied on a drawing of the holotype by Blow and Banner (1962), which was interpreted as a slightly deformed specimen, so we followed the well defined concept of this species set out by Blow (1969, 1979). The new holotype SEM of tripartita (Koch) (Pl. 11.14, Figs. 1-3) clearly shows, however, the large, robust, subspherical, test of this species, which is typical of the Oligocene, but is different from the specimens illustrated by Blow, and from D. cf. tripartita (Pearson and Wade, 2015). Dentoglobigerina eotripartita n. sp. is thus described to represent this smaller more compact morphotype typical of the Eocene, which was probably ancestral to the more robust tripartita sensu stricto. [Wade et al. 2018]

Dentoglobigerina eotripartita is distinguished from D. galavisi by its more compact morphology with 3 tightly coiled, more rapidly increasing chamber size in the final whorl and by possessing a more overarching and compressed final chamber. This species differs from D. tripartita by its smaller size, and less spherical, less compressed/reniform overall morphology, and from D. pseudovenezuelana by more tightly coiled chambers and tooth pointing down the opposing suture. [Wade et al. 2018]

References: