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Diconodinium dispersum
Diconodinium dispersum (Cookson and Eisenack, 1958) Eisenack and Cookson, 1960; emend. Morgan, 1977
Originally Palaeohystrichophora, subsequently Diconodinium.
Tax. jr. synonym of Diconodinium multispinum (Deflandre and Cookson, 1955) Eisenack and Cookson, 1960, according to Stover and Helby, 1987.
Holotype: Cookson and Eisenack, 1958, pl.10, fig.14; Morgan, 1977, pl.1, fig.2a-b
Locus typicus: Near Gingin, W Australia
Stratum typicum: Albian-Cenomanian
Original description: Cookson and Eisenack, 1958, p. 39: Palaeohystrichophora dispersa
Theca broadly fusiform, unequally divided by the transverse furrow, the larger "epitheca" being terminated by a short bifid process, the hypotheca by a sharply pointed process. The membrane of the theca is ornamented with rather widely dispersed small spine-like proceses with truncate apices.
Dimensions: Type - 80 x 53 Ám. Range - 64-90 x 38-62 Ám.
Emended description: Morgan, 1977, p. 127
Ambitus broadly fusiform, prolonged into a short, truncate apical horn, and a short, pointed antapical horn located close to the midline (Pl. 1, fig. 2). Epicyst larger than hypocyst. Apparent autophragm mostly thin, thickening at the apex to form a partly or wholly solid apical horn, and at the antapex to form a solid antapical horn. Surface densely covered with 2-3 Ám long, strongly capitate spines of uniform length on individual specimens. Paratabulation evident only at paracingulum and archeopyle, spines mostly nontabular. Paracingulum delineated by two slightly raised ridges bearing aligned ornamentation, individual paraplates not discernible. Parasulcus not clearly defined. Archeopyle la or IPa.
Dimensions: 64-90 Ám long and 38-62 Ám broad.
Affinities:
Cookson and Eisenack, 1958, p. 39: Palaeohystrichophora dispersa
P. dispersa can by distinguished from P. pellifera by the coarser nature of the spines, their truncate apices and wider dispersal.
Morgan, 1977, p. 127: The 2-3 Ám long, strongly capitate spines are characteristic of D. dispersum. For discussion of other species, see treatment of D. arcticum.
Originally Palaeohystrichophora, subsequently Diconodinium.
Tax. jr. synonym of Diconodinium multispinum (Deflandre and Cookson, 1955) Eisenack and Cookson, 1960, according to Stover and Helby, 1987.
Holotype: Cookson and Eisenack, 1958, pl.10, fig.14; Morgan, 1977, pl.1, fig.2a-b
Locus typicus: Near Gingin, W Australia
Stratum typicum: Albian-Cenomanian
Original description: Cookson and Eisenack, 1958, p. 39: Palaeohystrichophora dispersa
Theca broadly fusiform, unequally divided by the transverse furrow, the larger "epitheca" being terminated by a short bifid process, the hypotheca by a sharply pointed process. The membrane of the theca is ornamented with rather widely dispersed small spine-like proceses with truncate apices.
Dimensions: Type - 80 x 53 Ám. Range - 64-90 x 38-62 Ám.
Emended description: Morgan, 1977, p. 127
Ambitus broadly fusiform, prolonged into a short, truncate apical horn, and a short, pointed antapical horn located close to the midline (Pl. 1, fig. 2). Epicyst larger than hypocyst. Apparent autophragm mostly thin, thickening at the apex to form a partly or wholly solid apical horn, and at the antapex to form a solid antapical horn. Surface densely covered with 2-3 Ám long, strongly capitate spines of uniform length on individual specimens. Paratabulation evident only at paracingulum and archeopyle, spines mostly nontabular. Paracingulum delineated by two slightly raised ridges bearing aligned ornamentation, individual paraplates not discernible. Parasulcus not clearly defined. Archeopyle la or IPa.
Dimensions: 64-90 Ám long and 38-62 Ám broad.
Affinities:
Cookson and Eisenack, 1958, p. 39: Palaeohystrichophora dispersa
P. dispersa can by distinguished from P. pellifera by the coarser nature of the spines, their truncate apices and wider dispersal.
Morgan, 1977, p. 127: The 2-3 Ám long, strongly capitate spines are characteristic of D. dispersum. For discussion of other species, see treatment of D. arcticum.