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Cordosphaeridium gracile
Cordospaeridium gracile, (Eisenack, 1954b, p.66, pl.8, fig.17; pl.10, figs.3–8; pl.12, figs.7,21), Davey and Williams, 1966b, p.84; Emendation: Davey and Williams, 1966b, p.84–85, as Cordosphaeridium gracile
Originally Hystrichosphaeridium inodes ssp. gracile, subsequently Cordosphaeridium inodes ssp. gracile, thirdly (and now) Cordosphaeridium gracile, fourthly Tityrosphaeridium gracile.
Sarjeant, 1981, transferred this species to Tityrosphaeridium Sarjeant, 1981. Lentin and Williams, 1985, retained it in Cordosphaeridium.
Holotype: Eisenack, 1954, pl.10, fig.5
Locus typicus: N Samland, Russia
Stratum typicum: Early Oligocene
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Original description as Hystrichospaeridium inodes subsp. gracilis: [Eisenack, 1954, p. 66]: (Translation: LPP):
Diagnosis:
A subspecies of H. inodes Klumpp 1953 with following features: central body round to oval, in general larger than that of the root-species, the appendages are longer, significantly thinner and also of rather equal length.
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Emended description as Cordosphaeridium gracile:
Davey and Williams, 1966, p. 85:
Diagnosis:
Spherical to sub-spherical fibrous central body bearing small number of fibrous processes. Processes cylindrical, solid, erect, simple or branched and distinctly digitate: intratabular, one per plate area, number never less than 19 or greater than 20.
Archaeopyle apical, haplotabular, and reflected tabulation that of the genus Cordosphaeridium
Description:
The central body is characterized by a thick two-layered wall which is up to 2 µm in thickness. The processes are strongly fibrous, the fibres radiating outwards from the base of the processes over the surface of the central body and when branched have a characteristic Y-shape. The single sulcal process is always included within the cingulum series.
Dimensions:
Holotype: diameter of central body 77 µm, overall diameter 166 µm, length of processes 46-52 µm.
Range: diameter of central body 45-90 µm, (mean 69 µm), overall diameter 115-176 µm.
Range of London Clay specimens: diameter of central body 50-71 µm, length of processes 20-43 µm. 12 specimens measured.
Affinities:
Because of the observed differences to C. inodes, namely the variable thickness of the periphragm and endophragm, the absence of a narrow hollow space at the base of the processes, the solid structure and peculiar branching of the processes it is felt that Eisenack's subspecies merits raising to the specific level.
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Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Cordosphaeridium gracile (Eisenack, 1954b) emend. Davey and Williams, 1966b. Diagnosis from Eisenack (1954b): A subspecies of H.inodes with the following characteristic features. Central body spherical to ovoidal, generally larger than H.inodes, and with longer processes that are more slender, and of equal length. Davey and Williams (1966b) note that there are never more than 20 processes. Gocht (1969) determined a process formula of 3', 6", 6c, 5"’, 1"”.
Size: holotype diameter of central body 77 µm, process length 46-52 µm, total diameter 166 µm.
Originally Hystrichosphaeridium inodes ssp. gracile, subsequently Cordosphaeridium inodes ssp. gracile, thirdly (and now) Cordosphaeridium gracile, fourthly Tityrosphaeridium gracile.
Sarjeant, 1981, transferred this species to Tityrosphaeridium Sarjeant, 1981. Lentin and Williams, 1985, retained it in Cordosphaeridium.
Holotype: Eisenack, 1954, pl.10, fig.5
Locus typicus: N Samland, Russia
Stratum typicum: Early Oligocene
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Original description as Hystrichospaeridium inodes subsp. gracilis: [Eisenack, 1954, p. 66]: (Translation: LPP):
Diagnosis:
A subspecies of H. inodes Klumpp 1953 with following features: central body round to oval, in general larger than that of the root-species, the appendages are longer, significantly thinner and also of rather equal length.
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Emended description as Cordosphaeridium gracile:
Davey and Williams, 1966, p. 85:
Diagnosis:
Spherical to sub-spherical fibrous central body bearing small number of fibrous processes. Processes cylindrical, solid, erect, simple or branched and distinctly digitate: intratabular, one per plate area, number never less than 19 or greater than 20.
Archaeopyle apical, haplotabular, and reflected tabulation that of the genus Cordosphaeridium
Description:
The central body is characterized by a thick two-layered wall which is up to 2 µm in thickness. The processes are strongly fibrous, the fibres radiating outwards from the base of the processes over the surface of the central body and when branched have a characteristic Y-shape. The single sulcal process is always included within the cingulum series.
Dimensions:
Holotype: diameter of central body 77 µm, overall diameter 166 µm, length of processes 46-52 µm.
Range: diameter of central body 45-90 µm, (mean 69 µm), overall diameter 115-176 µm.
Range of London Clay specimens: diameter of central body 50-71 µm, length of processes 20-43 µm. 12 specimens measured.
Affinities:
Because of the observed differences to C. inodes, namely the variable thickness of the periphragm and endophragm, the absence of a narrow hollow space at the base of the processes, the solid structure and peculiar branching of the processes it is felt that Eisenack's subspecies merits raising to the specific level.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Cordosphaeridium gracile (Eisenack, 1954b) emend. Davey and Williams, 1966b. Diagnosis from Eisenack (1954b): A subspecies of H.inodes with the following characteristic features. Central body spherical to ovoidal, generally larger than H.inodes, and with longer processes that are more slender, and of equal length. Davey and Williams (1966b) note that there are never more than 20 processes. Gocht (1969) determined a process formula of 3', 6", 6c, 5"’, 1"”.
Size: holotype diameter of central body 77 µm, process length 46-52 µm, total diameter 166 µm.