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Pterodinium cornutum
Pterodinium? cornutum Cookson and Eisenack, 1962
Originally Pterodinium, subsequently (and now) Pterodinium?, thirdly Gonyaulacysta. Jan du Chêne et al. (1986a, p.274) questionably retained this species in Pterodinium. Questionable assignment: Stover and Evitt (1978, p.183). Yun, 1981 transferred this species to Gonyaulacysta Deflandre, 1964; however, Jan du Chêne et al., 1986 retained it in Pterodinium.
Holotype: Cookson and Eisenack, 1962, pl.3, fig.1-3; Jan du Chêne et al., 1986, pl.90, fig.1
Paratypes: Cookson and Eisenack, 1962
Locus typicus: Perth Basin, Metropolitan area, Caversham, Rakich"s bore, between 350 and 355 ft; Western Australia
Stratum typicum: Aptian-Albian
Original diagnosis: Cookson and Eisenack, 1962, p.490
Shell oval, with a thin hyaline outer membrane which forms the short, hollow, cylindrical apical horn, the borders of the deep, narrow girdle, and the high and smooth or finely serrate borders of the fields. The tabulation appears to be 3", 6", 6""", 1"""". A pylome is developed in the epitheca. In the example shown in plate 3, figs. 5-6, which is doubtfully referred to this species, a longitudinal furrow extending from apex to antapex is present. In this example the borders of the fields, especially those of the ventral surface, are more strongly serrated than those of the type and two paratypes.
Dimensions: Holotype: Overall length 83 µm; over-all breadth 76 µm, shell 62x48 µm; Range: Over-all length 78-86 µm; over-all breadth 70-76 µm; shell 52-62 x 48-58 µm.
Affinities:
Cookson and Eisenack, 1962, p.490: This species differs from both P. alatum Eisenack (1958, p.395) and P. magnoserratum in the development of a distinct apical horn. It also differs from the latter in the somewhat lower ledges and finer serrations.
Originally Pterodinium, subsequently (and now) Pterodinium?, thirdly Gonyaulacysta. Jan du Chêne et al. (1986a, p.274) questionably retained this species in Pterodinium. Questionable assignment: Stover and Evitt (1978, p.183). Yun, 1981 transferred this species to Gonyaulacysta Deflandre, 1964; however, Jan du Chêne et al., 1986 retained it in Pterodinium.
Holotype: Cookson and Eisenack, 1962, pl.3, fig.1-3; Jan du Chêne et al., 1986, pl.90, fig.1
Paratypes: Cookson and Eisenack, 1962
Locus typicus: Perth Basin, Metropolitan area, Caversham, Rakich"s bore, between 350 and 355 ft; Western Australia
Stratum typicum: Aptian-Albian
Original diagnosis: Cookson and Eisenack, 1962, p.490
Shell oval, with a thin hyaline outer membrane which forms the short, hollow, cylindrical apical horn, the borders of the deep, narrow girdle, and the high and smooth or finely serrate borders of the fields. The tabulation appears to be 3", 6", 6""", 1"""". A pylome is developed in the epitheca. In the example shown in plate 3, figs. 5-6, which is doubtfully referred to this species, a longitudinal furrow extending from apex to antapex is present. In this example the borders of the fields, especially those of the ventral surface, are more strongly serrated than those of the type and two paratypes.
Dimensions: Holotype: Overall length 83 µm; over-all breadth 76 µm, shell 62x48 µm; Range: Over-all length 78-86 µm; over-all breadth 70-76 µm; shell 52-62 x 48-58 µm.
Affinities:
Cookson and Eisenack, 1962, p.490: This species differs from both P. alatum Eisenack (1958, p.395) and P. magnoserratum in the development of a distinct apical horn. It also differs from the latter in the somewhat lower ledges and finer serrations.