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Diconodinium micropunctatum
From Fensome et al., 2019:
Diconodinium micropunctatum Backhouse, 1988, p.84, pl.25, figs.10a–b,11; pl.26, figs.1a–b. Holotype: Backhouse, 1988, pl.26,
figs.1a–b; Fensome et al., 1996, figs.3–4 — p.2227. Age: early Aptian.
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Original description: Backhouse, 1988, p.84
Cyst small, proximate, subovoid to biconical; epicyst and hypocyst approximately equal in size. Apical horn short (3 µm) solid and truncate; antapical horn usually a short acicular process offset slightly to the left. Autophragm 0.5 m thick, entirely covered by continuous longitudinal grooves and ridges. Distance between ridges approximately 1 µm. Grooves lined by rows of closely spaced shallow foveolae, that impart a finely punctate appearance to the autophragm. Paratabulation expressed only by archeopyle and paracingulum. Paracingulum, 4 to 6 µm wide, indicated bv transverse ridgcs 0.5 µm high, offset approximately 3 µm. Parasulus not indicated. Archeopyle intercalary, type la (2a only), standard hexa, seldom clearly observed; operculum free.
Dimensions: Length of holotype 44 µm, width 37 µm. Range of length (17 specimens) 34(42)51 µm, width 25(33)38 µm.
Affinities:
Backhouse, 1988, p.84: Diconodinium micropunctatum is distinguished from other species of Diconodinium by its small size and finely grooved foveolate surface. Laciniadinium tenuistriatum (Eisenack and Cookson) Morgan 1977 is larger than D. micropunctatum and lacks foveolae.
Diconodinium micropunctatum Backhouse, 1988, p.84, pl.25, figs.10a–b,11; pl.26, figs.1a–b. Holotype: Backhouse, 1988, pl.26,
figs.1a–b; Fensome et al., 1996, figs.3–4 — p.2227. Age: early Aptian.
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Original description: Backhouse, 1988, p.84
Cyst small, proximate, subovoid to biconical; epicyst and hypocyst approximately equal in size. Apical horn short (3 µm) solid and truncate; antapical horn usually a short acicular process offset slightly to the left. Autophragm 0.5 m thick, entirely covered by continuous longitudinal grooves and ridges. Distance between ridges approximately 1 µm. Grooves lined by rows of closely spaced shallow foveolae, that impart a finely punctate appearance to the autophragm. Paratabulation expressed only by archeopyle and paracingulum. Paracingulum, 4 to 6 µm wide, indicated bv transverse ridgcs 0.5 µm high, offset approximately 3 µm. Parasulus not indicated. Archeopyle intercalary, type la (2a only), standard hexa, seldom clearly observed; operculum free.
Dimensions: Length of holotype 44 µm, width 37 µm. Range of length (17 specimens) 34(42)51 µm, width 25(33)38 µm.
Affinities:
Backhouse, 1988, p.84: Diconodinium micropunctatum is distinguished from other species of Diconodinium by its small size and finely grooved foveolate surface. Laciniadinium tenuistriatum (Eisenack and Cookson) Morgan 1977 is larger than D. micropunctatum and lacks foveolae.