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Aptea uncinata
From Fensome et al., 2019:
Aptea uncinata, (Norvick, 1975, p.74–75, pl.8, figs.11–12) Fensome et al., 2019a, p.19.
Holotype: Norvick, 1975, pl.8, fig.11; Fauconnier and Masure, 2004, pl.17, figs.10–11; Fensome et al., 2019a, fig.12F.
Originally Adnatosphaeridium, subsequently Cyclonephelium, thirdly (and now) Aptea.
Age: Cenomanian.
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Originally Adnatosphaeridium, subsequently (and now) Cyclonephelium.
Holotype: Norvick, 1976, pl.8, fig.11
Paratype: Norvick, 1976
Locus typicus: Bathurst Island no. 2 well, Australia
Stratum typicum: Cenomanian.
Original diagnosis: Norvick, 1976, p.74: Adnatosphaeridium uncinatum
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 parallelsided. 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: Norvick, 1976, p.74: Adnatosphaeridium uncinatum
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 3-5 µm apart. They are 0.5-1 µm in diameter (most are about 1 µm) and 5-10 µm in length. Distally they divide into ribbon-like aculei (0.5-1 µm wide), which becorne recurved and connect with those from adjacent processes. The aculei bear no spines and are seldom branched. The overall appaerence of the processes is of a series of simple loops standing out from the central body wall. They are varible 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(61)71 µm for 28 examples.
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Comments Fensome et al., 2019a:
In his diagnosis of Adnatosphaeridium uncinatum, Norvick (Citation1976, p. 74) described the ornament as follows: ‘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’.
In the description, Norvick (Citation1976, p. 75) expanded on the details as follows:
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 variably arranged but appear to be more closely set around the periphery. They are slightly longer at the antapex. The dorsal and ventral faces sometimes bear slightly smaller processes, arranged in soleate and linear complexes.
Thus, although some apparently paratabulation-related arrangement to the ornament exists, as does some differentiation between dorsoventral and lateral surfaces, the dorsoventral surfaces are not entirely devoid of ornament. This distribution, together with the linked (i.e. linear) nature of the processes, prescribes an assignment to Aptea.
Cyclonephelium compactum has dorsoventral areas devoid of ornament, which is typically more complex than that of Aptea uncinata. Aptea polymorpha has distinct muri rather than linked processes. The arrangement of the processes into soleate complexes in Aptea uncinata is not readily apparent in the illustrations of the type material – although the ornament is clearly bunched, the bunches likely reflecting tabulation. This might be useful as a diagnostic criterion for the species, but was not apparent in the material newly illustrated herein.
Aptea uncinata, (Norvick, 1975, p.74–75, pl.8, figs.11–12) Fensome et al., 2019a, p.19.
Holotype: Norvick, 1975, pl.8, fig.11; Fauconnier and Masure, 2004, pl.17, figs.10–11; Fensome et al., 2019a, fig.12F.
Originally Adnatosphaeridium, subsequently Cyclonephelium, thirdly (and now) Aptea.
Age: Cenomanian.
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Originally Adnatosphaeridium, subsequently (and now) Cyclonephelium.
Holotype: Norvick, 1976, pl.8, fig.11
Paratype: Norvick, 1976
Locus typicus: Bathurst Island no. 2 well, Australia
Stratum typicum: Cenomanian.
Original diagnosis: Norvick, 1976, p.74: Adnatosphaeridium uncinatum
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 parallelsided. 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: Norvick, 1976, p.74: Adnatosphaeridium uncinatum
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 3-5 µm apart. They are 0.5-1 µm in diameter (most are about 1 µm) and 5-10 µm in length. Distally they divide into ribbon-like aculei (0.5-1 µm wide), which becorne recurved and connect with those from adjacent processes. The aculei bear no spines and are seldom branched. The overall appaerence of the processes is of a series of simple loops standing out from the central body wall. They are varible 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(61)71 µm for 28 examples.
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Comments Fensome et al., 2019a:
In his diagnosis of Adnatosphaeridium uncinatum, Norvick (Citation1976, p. 74) described the ornament as follows: ‘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’.
In the description, Norvick (Citation1976, p. 75) expanded on the details as follows:
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 variably arranged but appear to be more closely set around the periphery. They are slightly longer at the antapex. The dorsal and ventral faces sometimes bear slightly smaller processes, arranged in soleate and linear complexes.
Thus, although some apparently paratabulation-related arrangement to the ornament exists, as does some differentiation between dorsoventral and lateral surfaces, the dorsoventral surfaces are not entirely devoid of ornament. This distribution, together with the linked (i.e. linear) nature of the processes, prescribes an assignment to Aptea.
Cyclonephelium compactum has dorsoventral areas devoid of ornament, which is typically more complex than that of Aptea uncinata. Aptea polymorpha has distinct muri rather than linked processes. The arrangement of the processes into soleate complexes in Aptea uncinata is not readily apparent in the illustrations of the type material – although the ornament is clearly bunched, the bunches likely reflecting tabulation. This might be useful as a diagnostic criterion for the species, but was not apparent in the material newly illustrated herein.