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Cerbia formosa
From Fensome et al., 2019:
Cerbia formosa Mao Shaozhi and Norris, 1988, p.31–32, pl.1, figs.9–10; text-fig.8, nos.1–2. Holotype: Mao Shaozhi and
Norris, 1988, pl.1, fig.9; text-fig.8, no.2; Fensome et al., 2019a, fig.14M. Originally Cerbia, subsequently Tenua
Eisenack, thirdly (and now) Cerbia?. Fensome et al. (2019a, p.35) questionably retained this species in Cerbia.
Taxonomic junior synonym: Cerbia (al. Tenua) suturispinosa, according to Fensome et al. (2019a, p.35). Age: Late
Eocene–Early Oligocene.
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Original description: [Mao Shaozhi and Norris, 1988, p. 31-32]:
Diagnosis:
Cyst proximate to proximochorate, dorsoventrally compressed, with an apical prominence. Antapical end either rounded or slightly concave. Processes penitabular, slender, and sinuous, partly connected proximally forming arcuate and soleate complexes; mostly acuminate, capitate, and bifurcate, seldom trifurcate distally.
Archeopyle apical, type (4A); operculum typically detached but in situ. Archeopyle suture zigzag, with accessory sutures indicating six precingular plates.
Cingulum slightly levorotatory, indicated by alignment of processes. Sulcus broader towards antapex; sulcal notch offset to left on ventral surface. Tabulation indicated by penitabular processes, gonyaulacacean; possible formula of 4", 6", Xc, 6""", 1p, 1"""".
Description:
Ambitus rounded pentagonal to rounded biconical, prolonged into an obtuse and short tapering apical horn. Hypotract either semicircular or, more commonly, with two poorly developed, unequal antapical lobes; left one slightly longer than right one.
Processes relatively long (usually 6 to 8 µm, sometimes up to 10 to 12 µm), narrow (usually 0.5 to 1 µm), sinuous, delicate; usually secondarily flattened in random orientation. Plate boundaries usually obscured.
Cingulum delineated by processes about 8 to 10 µm in breadth.
Dimensions:
Length (including operculum) 65 to 68 µm (holotype 65 µm), width 41 to 68 µm (holotype 63 µm).
Affinites:
Cerbia formosa is closely comparable to C. tabulata (Davey and Verdier, 1974), but the latter differs in having short, stout, capitate processes, which are rarely branched distally; in C. formosa the processes are long, slender, curved, and frequently branched. In addition, the processes of C. formosa are less clearly tabular than those of C. tabulata.
Cerbia formosa Mao Shaozhi and Norris, 1988, p.31–32, pl.1, figs.9–10; text-fig.8, nos.1–2. Holotype: Mao Shaozhi and
Norris, 1988, pl.1, fig.9; text-fig.8, no.2; Fensome et al., 2019a, fig.14M. Originally Cerbia, subsequently Tenua
Eisenack, thirdly (and now) Cerbia?. Fensome et al. (2019a, p.35) questionably retained this species in Cerbia.
Taxonomic junior synonym: Cerbia (al. Tenua) suturispinosa, according to Fensome et al. (2019a, p.35). Age: Late
Eocene–Early Oligocene.
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Original description: [Mao Shaozhi and Norris, 1988, p. 31-32]:
Diagnosis:
Cyst proximate to proximochorate, dorsoventrally compressed, with an apical prominence. Antapical end either rounded or slightly concave. Processes penitabular, slender, and sinuous, partly connected proximally forming arcuate and soleate complexes; mostly acuminate, capitate, and bifurcate, seldom trifurcate distally.
Archeopyle apical, type (4A); operculum typically detached but in situ. Archeopyle suture zigzag, with accessory sutures indicating six precingular plates.
Cingulum slightly levorotatory, indicated by alignment of processes. Sulcus broader towards antapex; sulcal notch offset to left on ventral surface. Tabulation indicated by penitabular processes, gonyaulacacean; possible formula of 4", 6", Xc, 6""", 1p, 1"""".
Description:
Ambitus rounded pentagonal to rounded biconical, prolonged into an obtuse and short tapering apical horn. Hypotract either semicircular or, more commonly, with two poorly developed, unequal antapical lobes; left one slightly longer than right one.
Processes relatively long (usually 6 to 8 µm, sometimes up to 10 to 12 µm), narrow (usually 0.5 to 1 µm), sinuous, delicate; usually secondarily flattened in random orientation. Plate boundaries usually obscured.
Cingulum delineated by processes about 8 to 10 µm in breadth.
Dimensions:
Length (including operculum) 65 to 68 µm (holotype 65 µm), width 41 to 68 µm (holotype 63 µm).
Affinites:
Cerbia formosa is closely comparable to C. tabulata (Davey and Verdier, 1974), but the latter differs in having short, stout, capitate processes, which are rarely branched distally; in C. formosa the processes are long, slender, curved, and frequently branched. In addition, the processes of C. formosa are less clearly tabular than those of C. tabulata.