Williams, Lentin and Fensome 1998 - Lentin and Williams Index of Fossil Dinoflagellates

Achomosphaera improcera, Islam, 1983c, p. 80-81, pl.1, figs.1–2

Holotype: Islam, 1983c, pl.1, fig.1.
Paratype: Islam, 1983
Locus typicus: Shapley Heath, England
Stratum typicum: Middle Eocene
Age: Early-Mid Eocene

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Original description: [Islam, 1983, p. 80]:

Diagnosis:
Cyst subspherical to ellipsoidal, proximochorate and biphragmal; endophragm psilate and chagrinate; periphragm psilate; processes solid and hollow with both ends closed or distally open, proximally wide and sometimes joining with adjacent ones, distally tri- or bifurcate with slightly bifid tips probably indicating gonal and intergonal positions respectively, pairs of processes particularly in paracingular area sometimes joined with high proximal membrane, up to a third of mean cyst diameter in length but generally shorter; a rudimentary apical boss frequently present; paratabulation not determinable but foldings in periphragm may produce a similitude;
archeopyle precingular type P.