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Cordosphaeridium latispinosum
Cordosphaeridium latispinosum Davey and Williams, 1966
Now Achilleodinium. Originally Cordosphaeridium, subsequently (and now) Achilleodinium, thirdly Tityrosphaeridium?.
Sarjeant, 1981, provisionally transferred this species to Tityrosphaeridium Sarjeant, 1981. Lentin and Williams, 1985, retained it in Achilleodinium Eaton, 1976.
Holotype: Davey and Williams 1966, pl.5, fig.8; Bujak et al., 1980, pl.8, figs.7-9
Locus typicus: London Clay, Kent, England
Stratum typicum: Early Eocene
Original diagnosis: Davey and Williams, 1966, p.88
Ellipsoidal central body having a finely striate periphragm from which arise two types of processes: broad ovoidal to quadrate ones, closed or with restricted distal opening, and slender oblate processes. Larger processes reflecting a tabulation of 1", 6", 6""", 1""""; smaller ones restricted to sulcal and cingulum regions.
Dimensions: holotype: diameter of central body 56x61 µm, length of processes
up to 22 µm. Range: diameter of central body 50-77 µm, length of processes 11-24 µm, width of broad processes up to 27 µm.
Original description: Davey and Williams, 1966, p. 88
The broad processes of Cordosphaeridium latispinosum are quadrate or ellipsoidal in cross-section proximally. They taper distally and have a slightly fibrous wall which may be perforate with small lateral spines: the broad processes are found on the apical, pre- and postcingular, posterior intercalary and antapical plate areas. The slender processes appear to be sulcal or cingular processes.
They can be simple or bifurcate, distally they are oblate or accuminate. The striae on the periphragm radiate outwards from the bases of the processes over the surface of the central body.
Affinities:
Davey and Williams, 1966, p. 88: C. Iatispinosum differs from ?Litosphaeridium truncigerum Deflandre 1937 from the Upper Cretaceous of France, in the nature of the broad processes. In ?L. truncigerum these are widely open with denticulate margins, whereas in C. Iatispinosum they are closed or have a restricted elongate opening with lateral spines developed.
Now Achilleodinium. Originally Cordosphaeridium, subsequently (and now) Achilleodinium, thirdly Tityrosphaeridium?.
Sarjeant, 1981, provisionally transferred this species to Tityrosphaeridium Sarjeant, 1981. Lentin and Williams, 1985, retained it in Achilleodinium Eaton, 1976.
Holotype: Davey and Williams 1966, pl.5, fig.8; Bujak et al., 1980, pl.8, figs.7-9
Locus typicus: London Clay, Kent, England
Stratum typicum: Early Eocene
Original diagnosis: Davey and Williams, 1966, p.88
Ellipsoidal central body having a finely striate periphragm from which arise two types of processes: broad ovoidal to quadrate ones, closed or with restricted distal opening, and slender oblate processes. Larger processes reflecting a tabulation of 1", 6", 6""", 1""""; smaller ones restricted to sulcal and cingulum regions.
Dimensions: holotype: diameter of central body 56x61 µm, length of processes
up to 22 µm. Range: diameter of central body 50-77 µm, length of processes 11-24 µm, width of broad processes up to 27 µm.
Original description: Davey and Williams, 1966, p. 88
The broad processes of Cordosphaeridium latispinosum are quadrate or ellipsoidal in cross-section proximally. They taper distally and have a slightly fibrous wall which may be perforate with small lateral spines: the broad processes are found on the apical, pre- and postcingular, posterior intercalary and antapical plate areas. The slender processes appear to be sulcal or cingular processes.
They can be simple or bifurcate, distally they are oblate or accuminate. The striae on the periphragm radiate outwards from the bases of the processes over the surface of the central body.
Affinities:
Davey and Williams, 1966, p. 88: C. Iatispinosum differs from ?Litosphaeridium truncigerum Deflandre 1937 from the Upper Cretaceous of France, in the nature of the broad processes. In ?L. truncigerum these are widely open with denticulate margins, whereas in C. Iatispinosum they are closed or have a restricted elongate opening with lateral spines developed.