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Cordosphaeridium fasciatum
Cordosphaeridium fasciatum, Davey and Williams, 1966
Now Kleithriasphaeridium. Originally Cordosphaeridium?, subsequently (and now) Kleithriasphaeridium.
Davey and Williams, 1966, questionably included this species in Cordosphaeridium.
Holotype: Davey and Williams, 1966, pl.7, figs.5,6
Locus typicus: Heslerton, England
Stratum typicum: Barremian
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Original description: [Davey and Williams, 1966, p. 90-91]:
Diagnosis:
Spherical to sub-spherical central body composed of reticulate endophragm of fibrous periphragm.
Processes, composed of periphragm, smooth or slightly fibrous, short, wide and tubiform, always hollow and denticulate distally.
Description:
From the base of each process, thickenings of the periphragm radiate over the surface of the central body joining together with similar thickenings from neighbouring processes. The reticulate nature of the endophragm can sometimes be observed where the periphragm thins midway between processes and also at the bases of the processes when one is able to view directly down the centre of a vertical process (Pl. 7, fig. 6). The processes have parallel or sub-parallel sides throughout their length. There are 18 to 20 processes,
an apical archaeopyle usually being present. The shape and form of the archaeopyle is difficult to determine and a detached apical region has not, as yet, been observed. However the archaeopyle is thought to be haplotabular and the spines to have an inferred reflected tabulation of 1", 6", 6c, 5""", 1"""" and 0-2s.
Dimensions:
Holotype: diameter of central body 40x40 µm, length of processes 11-16 µm, number of processes 19.
Range: diameter of central body 35-47 µm, length of processes 12-25 µm.
Affinities:
The short, wide tabular processes differentiate this species from ?C. eoinodes (Eisenack) and the nature of the periphragm on the central body is probably different although this was not commented on in the original diagnosis or description. The nature of the periphragm on the surface of the central body and when composing the processes of Hystrichosphaeridium radiculatum and H. mantelli is very similar to C. fasciatum perhaps indicating a relationship between the three species. Each form possesses a distinctive type of process and the two forms of Hystrichosphaeridium have a greater number of processes than does C. fasciatum. The type of archaeopyle is a very important factor in determining the above relationships but unfortunately the exact type of archaeopyle has not been determined as yet.
Now Kleithriasphaeridium. Originally Cordosphaeridium?, subsequently (and now) Kleithriasphaeridium.
Davey and Williams, 1966, questionably included this species in Cordosphaeridium.
Holotype: Davey and Williams, 1966, pl.7, figs.5,6
Locus typicus: Heslerton, England
Stratum typicum: Barremian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Davey and Williams, 1966, p. 90-91]:
Diagnosis:
Spherical to sub-spherical central body composed of reticulate endophragm of fibrous periphragm.
Processes, composed of periphragm, smooth or slightly fibrous, short, wide and tubiform, always hollow and denticulate distally.
Description:
From the base of each process, thickenings of the periphragm radiate over the surface of the central body joining together with similar thickenings from neighbouring processes. The reticulate nature of the endophragm can sometimes be observed where the periphragm thins midway between processes and also at the bases of the processes when one is able to view directly down the centre of a vertical process (Pl. 7, fig. 6). The processes have parallel or sub-parallel sides throughout their length. There are 18 to 20 processes,
an apical archaeopyle usually being present. The shape and form of the archaeopyle is difficult to determine and a detached apical region has not, as yet, been observed. However the archaeopyle is thought to be haplotabular and the spines to have an inferred reflected tabulation of 1", 6", 6c, 5""", 1"""" and 0-2s.
Dimensions:
Holotype: diameter of central body 40x40 µm, length of processes 11-16 µm, number of processes 19.
Range: diameter of central body 35-47 µm, length of processes 12-25 µm.
Affinities:
The short, wide tabular processes differentiate this species from ?C. eoinodes (Eisenack) and the nature of the periphragm on the central body is probably different although this was not commented on in the original diagnosis or description. The nature of the periphragm on the surface of the central body and when composing the processes of Hystrichosphaeridium radiculatum and H. mantelli is very similar to C. fasciatum perhaps indicating a relationship between the three species. Each form possesses a distinctive type of process and the two forms of Hystrichosphaeridium have a greater number of processes than does C. fasciatum. The type of archaeopyle is a very important factor in determining the above relationships but unfortunately the exact type of archaeopyle has not been determined as yet.