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Melitasphaeridium asterium
Melitasphaeridium asterium (Eaton, 1976) Bujak et al., 1980
Originally Hystrichosphaeridium, subsequently (and now) Melitasphaeridium.
Holotype: Eaton, 1976, pl.11, figs.7-8; Bujak et al., 1980, pl.2, fig.3
Locus typicus: Whitecliff Bay, Isle of Wight, England.
Stratum typicum: Late Eocene
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Melitasphaeridium asterium (Eaton, 1976) Bujak et al., 1980. This species has a subcircular to rounded polygonal outline and a smooth surface. Processes about 20, tubular and usually slender and fairly constant in width. Each process is surmounted by a wide distal platform with usually 10 to 15 marginal aculei. Archeopyle precingular. Size: cyst body (without operculum) 22 x 22 to 30 x 34 µm. Length of processes up to 20 µm
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Original diagnosis: Eaton, 1976, p. 273: Hystrichosphaeridium asterium
Cyst body has a subcircular or rounded polygonal outline and a smooth surface. Processes about 20, tubular and usually slender and fairly constant in breadth. Each process is surmounted by a wide distal platform with usually 10 to 15 marginal aculei. Archaeopyle apical.
Dimensions: Holotype: cyst body (without operculum) 27 X 32 Ám; length of processes up to 13 Ám. Observed range: cyst body (without operculum) 22 x 22
to 30 x 34 Ám; length of processes up to 20 Ám. (n = 4).
Affinities:
Eaton, 1976, p. 273: Hystrichosphaeridium asterium
None of the observed specimens is complete. The number of processes (about 20) indicates that there is one process per plate, reflecting the tabulation of the genus. The processes are occasionally expanded proximally-in one specimen (Pl. 11, fig. 9) one process shows considerable proximal expansion. The distal platforms which surmount each process are typically recurved, sometimes flat or slightly concave. Some processes show a reduction of the distal platform; these are similar to those of H. pseudorecurvatum Morgenroth 1966. Apart from the occasional presence of such processes, the small size of H. asterium and the distinctive form of the distal portion of its processes distinguish this species from all other described species of Hystrichosphaeridium.
Originally Hystrichosphaeridium, subsequently (and now) Melitasphaeridium.
Holotype: Eaton, 1976, pl.11, figs.7-8; Bujak et al., 1980, pl.2, fig.3
Locus typicus: Whitecliff Bay, Isle of Wight, England.
Stratum typicum: Late Eocene
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Melitasphaeridium asterium (Eaton, 1976) Bujak et al., 1980. This species has a subcircular to rounded polygonal outline and a smooth surface. Processes about 20, tubular and usually slender and fairly constant in width. Each process is surmounted by a wide distal platform with usually 10 to 15 marginal aculei. Archeopyle precingular. Size: cyst body (without operculum) 22 x 22 to 30 x 34 µm. Length of processes up to 20 µm
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Original diagnosis: Eaton, 1976, p. 273: Hystrichosphaeridium asterium
Cyst body has a subcircular or rounded polygonal outline and a smooth surface. Processes about 20, tubular and usually slender and fairly constant in breadth. Each process is surmounted by a wide distal platform with usually 10 to 15 marginal aculei. Archaeopyle apical.
Dimensions: Holotype: cyst body (without operculum) 27 X 32 Ám; length of processes up to 13 Ám. Observed range: cyst body (without operculum) 22 x 22
to 30 x 34 Ám; length of processes up to 20 Ám. (n = 4).
Affinities:
Eaton, 1976, p. 273: Hystrichosphaeridium asterium
None of the observed specimens is complete. The number of processes (about 20) indicates that there is one process per plate, reflecting the tabulation of the genus. The processes are occasionally expanded proximally-in one specimen (Pl. 11, fig. 9) one process shows considerable proximal expansion. The distal platforms which surmount each process are typically recurved, sometimes flat or slightly concave. Some processes show a reduction of the distal platform; these are similar to those of H. pseudorecurvatum Morgenroth 1966. Apart from the occasional presence of such processes, the small size of H. asterium and the distinctive form of the distal portion of its processes distinguish this species from all other described species of Hystrichosphaeridium.