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Tityrosphaeridium gracile
Tityrosphaeridium gracile (Eisenack, 1954) Sarjeant 1981; Emendation: Davey and Williams, 1966b, p.84–85, as Cordosphaeridium gracile.
Now Cordosphaeridium gracile. Originally Hystrichosphaeridium inodes ssp. gracile, subsequently Cordosphaeridium inodes ssp. gracile, thirdly (and now) Cordosphaeridium gracile, fourthly Tityrosphaerzdium gracile. Lentin and Williams, 1985 retained this species in Cordosphaeridium Eisenack, 1963.
Holotype: Eisenack 1954, pl.10, fig.5
Age: Oligocene
Original description: Eisenack, 1954, p. 66: Hystrichospaeridium inodes subsp. gracilis
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.
Emended description: Davey and Williams, 1966, p. 85: Cordosphaeridium gracile
Emended 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.
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.
Emended description: The central body is characterized by a thick two-layered wall which is up to 2 Ám 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.
Affinities: Davey and Williams, 1966, p. 86
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.
Supplemental description: Mehrota and Sarjeant, 1987, p. 157-158
Cyst chorate, skolochorate and intratabulate. Central body subspheroidal. Periphragm and endophragm closely appressed, except where periphragm gives rise to processes; periphragm finely punctate, endophragm (where separately seen) laevigate. Processes fibrous, tubular to lagenate, distally open with digitate or serrate margins. Paratabulation: 4", 6", 6c, 6""", 1p, 1"""", ?2s. Processes on the hypotract are somewhat broader than those on the epitract, the cingular processes being the thinnest. The antapical process is branched and quite prominent. A couple of slender processes present in the anterior ventral region are probably sulcals. Archaeopyle precingular (type P), formed by the loss of paraplate 3""; operculum free.
Now Cordosphaeridium gracile. Originally Hystrichosphaeridium inodes ssp. gracile, subsequently Cordosphaeridium inodes ssp. gracile, thirdly (and now) Cordosphaeridium gracile, fourthly Tityrosphaerzdium gracile. Lentin and Williams, 1985 retained this species in Cordosphaeridium Eisenack, 1963.
Holotype: Eisenack 1954, pl.10, fig.5
Age: Oligocene
Original description: Eisenack, 1954, p. 66: Hystrichospaeridium inodes subsp. gracilis
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.
Emended description: Davey and Williams, 1966, p. 85: Cordosphaeridium gracile
Emended 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.
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.
Emended description: The central body is characterized by a thick two-layered wall which is up to 2 Ám 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.
Affinities: Davey and Williams, 1966, p. 86
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.
Supplemental description: Mehrota and Sarjeant, 1987, p. 157-158
Cyst chorate, skolochorate and intratabulate. Central body subspheroidal. Periphragm and endophragm closely appressed, except where periphragm gives rise to processes; periphragm finely punctate, endophragm (where separately seen) laevigate. Processes fibrous, tubular to lagenate, distally open with digitate or serrate margins. Paratabulation: 4", 6", 6c, 6""", 1p, 1"""", ?2s. Processes on the hypotract are somewhat broader than those on the epitract, the cingular processes being the thinnest. The antapical process is branched and quite prominent. A couple of slender processes present in the anterior ventral region are probably sulcals. Archaeopyle precingular (type P), formed by the loss of paraplate 3""; operculum free.