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Rhombodinium minusculum
Rhombodinium? minisculum (Alberti, 1961) Lentin and Williams, 1973
Now Palaeotetradinium. Originally Wetzeliella subgen. Rhombodinium, subsequently Rhombodinium?, thirdly Inversidinium, fourthly (and now) Palaeotetradinium.
Tax. sr. synonym of Inversidinium exilimurum McLean, 1973, according to Stover and Evitt, 1978. Lentin and Williams, 1976 provisionally included this species in Rhombodinium. McLean, 1973 suggested that this species may belong to the genus Inversidinium McLean, 1973. Costa and Downie, 1979 transferred the species to Inversidinium; however, Lentin and Williams, 1981 retained it in Palaeotetradinium Deflandre, 1936.
Holotype: Alberti, 1961, pl.1, fig.10; pl.12, fig.4
Locus typicus: Hildesheim, Germany
Stratum typicum: Early Eocene
Translation Alberti, 1961: LPP
Original diagnosis: Alberti, 1961, p. 10: Wetzeliella miniscula
Shell flattened, almost rhomboedrical; wepitheca triangular slightly elongated. Lateral horns short, indented at the free ends. Transverse furrow indicated. Epitheca shorter than the inverse hat-shaped hypotheca. With two antapical bulges, seperated by parallel to the longitudinal direction running gap. Presumably with a delicate inner body. The shell membrane is transparent, yellowish. A transverse furrow is indicated on one side ( may be a fault). A pylome is questionable.
Now Palaeotetradinium. Originally Wetzeliella subgen. Rhombodinium, subsequently Rhombodinium?, thirdly Inversidinium, fourthly (and now) Palaeotetradinium.
Tax. sr. synonym of Inversidinium exilimurum McLean, 1973, according to Stover and Evitt, 1978. Lentin and Williams, 1976 provisionally included this species in Rhombodinium. McLean, 1973 suggested that this species may belong to the genus Inversidinium McLean, 1973. Costa and Downie, 1979 transferred the species to Inversidinium; however, Lentin and Williams, 1981 retained it in Palaeotetradinium Deflandre, 1936.
Holotype: Alberti, 1961, pl.1, fig.10; pl.12, fig.4
Locus typicus: Hildesheim, Germany
Stratum typicum: Early Eocene
Translation Alberti, 1961: LPP
Original diagnosis: Alberti, 1961, p. 10: Wetzeliella miniscula
Shell flattened, almost rhomboedrical; wepitheca triangular slightly elongated. Lateral horns short, indented at the free ends. Transverse furrow indicated. Epitheca shorter than the inverse hat-shaped hypotheca. With two antapical bulges, seperated by parallel to the longitudinal direction running gap. Presumably with a delicate inner body. The shell membrane is transparent, yellowish. A transverse furrow is indicated on one side ( may be a fault). A pylome is questionable.