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Adnatosphaeridium uncinatum

Adnatosphaeridium uncinatum, Norvick, 1976

Holotype: Norvick, 1976, pl.8, fig.11
Paratype: Norvick, 1976
Locus typicus: Bathurst Island no. 2 well, Australia
Stratum typicum: Cenomanian

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Original description: [Norvick, 1976, p. 74]:

Diagnosis:
Cyst chorate, dorsoventrally flattened. Central body thin walled, outline circular or with either one or two low antapical protuberances.
Processes numerous, short, solid, narrow, and parallel-sided. Processes divide distally into narrow, flattened, smooth, unbranched aculei, which unite with those from adjacent processes. Processes similar or slightly longer at the antapex. Tabulation and cingulum absent.
Archaeopyle apical, tetratabular, with a zig-zag or notched margin.

Description:
Dorsoventrally flattened chorate cyst, with a central body whose outline is circular or subcircular, sometimes with one or two unequal antapical protuberances. The wall is thin (less than 0.5 µm) and its surface is smooth or faintly granulate. The central body bears numerous straight, parallel-sided, solid processes with slightly expanded bases, about 3 to 5 µm apart. They are 0.5 to 1 µm in diameter (most are about 1 µm) and 5 to 10 µm in length. Distally they divide into ribbon-like aculei (0.5 to 1 µm wide), which become recurved and connect with those from adjacent processes. The aculei bear no spines and are seldom branched. The overall appearance of the processes is of a series of simple loops standing out from the central body wall. They are variable arranged but appear to be more closely set around the periphery. They are slightly longer at the antapex. The dorsal and ventral surfaces sometimes bear slightly smaller processes, arranged in soleate and linear complexes. No tabular pattern could be elucidated.
The archaeopyle is apical in position, with a zig-zag and sometimes notched margin. Detached tetratabular, six-sided opercula are common.

Dimensions:
The overall width is 51 µm (61 µm) 71 µm for 28 examples.
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