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Hystrichosphaeridium sheppeyense
Hystrichosphaeridium sheppeyense Davey and Williams 1966
Tax. jr. synonym of Hystrichosphaeridium (now Melitasphaeridium) pseudorecuruatum Morgenroth, 1966, according to Stover and Evitt, 1978.
Holotype: Davey and Williams 1966, pl.11, fig.3; Bujak et al., 1980, pl.2, figs.1-2
Locus typicus: Kent, England
Stratum typicum: Early Eocene
Original diagnosis: Davey and Williams, 1966, p. 69
Ovoidal central body with smooth or slightly granular surface. Processes tubular, open distally, approximately equal in length to radius of central body, terminating in a number of orthogonal or recurved spines.
Dimensions: holotype: overall diameter 59 by 57 µm, diameter of central body
29 by 31 µm, length of processes 14-18 µm, width of processes up to 2 µm, number of processes 26.
Original descrption: Davey and Williams, 1966, p. 69
The processes are relatively thick walled, the tubule being narrow and sometimes constricted. At the bases of some of the processes there are small proximal elevations or swellings. Distally the processes splay out into 2 to 7 spines or secae, up to 6 Ám long. An apical archaeopyle is usually present. The tabulation reflected by the processes is that of HystYichosphaeridium.
Affinities:
Davey and Williams, 1966, p. 69: H. sheppeyense differs from H. recurvatum (White) in being considerably smaller and possessing relatively short processes. The forms described and figured by Deflandre & Cookson (1955) and by Evit (1961) are identical in all respects except that the former, from the Senonian, is rather larger. Deflandre & Cookson"s figured specimen has an overall diameter of 90 µm, central body diameter of 44 by 51 µm and processes 16-26 µm in length.
Tax. jr. synonym of Hystrichosphaeridium (now Melitasphaeridium) pseudorecuruatum Morgenroth, 1966, according to Stover and Evitt, 1978.
Holotype: Davey and Williams 1966, pl.11, fig.3; Bujak et al., 1980, pl.2, figs.1-2
Locus typicus: Kent, England
Stratum typicum: Early Eocene
Original diagnosis: Davey and Williams, 1966, p. 69
Ovoidal central body with smooth or slightly granular surface. Processes tubular, open distally, approximately equal in length to radius of central body, terminating in a number of orthogonal or recurved spines.
Dimensions: holotype: overall diameter 59 by 57 µm, diameter of central body
29 by 31 µm, length of processes 14-18 µm, width of processes up to 2 µm, number of processes 26.
Original descrption: Davey and Williams, 1966, p. 69
The processes are relatively thick walled, the tubule being narrow and sometimes constricted. At the bases of some of the processes there are small proximal elevations or swellings. Distally the processes splay out into 2 to 7 spines or secae, up to 6 Ám long. An apical archaeopyle is usually present. The tabulation reflected by the processes is that of HystYichosphaeridium.
Affinities:
Davey and Williams, 1966, p. 69: H. sheppeyense differs from H. recurvatum (White) in being considerably smaller and possessing relatively short processes. The forms described and figured by Deflandre & Cookson (1955) and by Evit (1961) are identical in all respects except that the former, from the Senonian, is rather larger. Deflandre & Cookson"s figured specimen has an overall diameter of 90 µm, central body diameter of 44 by 51 µm and processes 16-26 µm in length.