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Polystephanephorus sarjeantii
Polystephanephorus sarjeantii Gitmez, 1970
NOW Emmetrocysta. Originally Polystephanephorus, subsequently (and now) Emmetrocysta, thirdly Hystrichosphaerina, fourthly Stiphrosphaeridium.
Holotype: Gitmez, 1970, pl.11, fig.4; text-fig.25; Fauconnier and Masure, 2004, pl.26, fig.7.
Locus typicus: Shaly clay from the base of the Kimmeridge Clay, Liostrea delta Bed, Osmington Mills, Dorset (OM 131), England
Stratum typicum: Early Kimmeridgian
Original diagnosis: Gitmez, 1970, p.291
Polystephanephorus having a spherical to subspherical shell, bearing I4 groups of processes together with 2 single processes. There is no connection between the adjacent groups. All processes of each group are connected distally by a ring trabecula. The number of the processes in the groups is variable, between 2 and 6. Reflected tabulation: ?", 6", 6""", 1p, 2s and 1"""". Surface of the shell smooth and transparent. Apical archaeopyle developed.
Dimensions: Holotype: shell length 40 µm, breadth 45 µm; process length 20-25 µm. Range of the English specimens (10 specimens measured): shell length 40-70 µm, breadth 35-60 µm; process length 20-28 µm. French specimens (6 specimens measured) shell length 42-60 µm, breadth 40-55 µm; process length 22-28 µm.
Original description: Gitmez, 1970, p.291-292
Central body subspherical or spherical in shape, with groups of complicated processes. In addition to the groups of processes, two single processes were observed, which are positional equivalents of the sulcus. These two single processes are foliate and furcate towards their distal ends. All the processes of each group separately rise up from the central body and are subsequently connected by bridge-like strands; near to their tips, they are foliate and fenestrate; at their tips, they are connected by a ring trabecula with denticulate edges. All the processes are solid.
The surface of the shell appears smooth and transparent; because of their transparency, identification of the processes was extremely difficult. An apical archaeopyle, slightly polygonal in shape, was seen in some of the specimens studied.
Affinities:
Gitmez, 1970, p.292: This new species of the genus Polystephanephorus differs from the previously described species in its more complicated processes. The processes are not connected proximally, as in P. urnaformis, and the branches are longer than the branches of P. calathus and P. paracalathus; they are not directed parallel to the shell surface; however the processes are linked by a ring trabecula as the other species of the genus.
P. sarjeantii is similar to Adnatosphaeridium caulleryi, but the arrangement and the manner of linkage of the processes are different.
NOW Emmetrocysta. Originally Polystephanephorus, subsequently (and now) Emmetrocysta, thirdly Hystrichosphaerina, fourthly Stiphrosphaeridium.
Holotype: Gitmez, 1970, pl.11, fig.4; text-fig.25; Fauconnier and Masure, 2004, pl.26, fig.7.
Locus typicus: Shaly clay from the base of the Kimmeridge Clay, Liostrea delta Bed, Osmington Mills, Dorset (OM 131), England
Stratum typicum: Early Kimmeridgian
Original diagnosis: Gitmez, 1970, p.291
Polystephanephorus having a spherical to subspherical shell, bearing I4 groups of processes together with 2 single processes. There is no connection between the adjacent groups. All processes of each group are connected distally by a ring trabecula. The number of the processes in the groups is variable, between 2 and 6. Reflected tabulation: ?", 6", 6""", 1p, 2s and 1"""". Surface of the shell smooth and transparent. Apical archaeopyle developed.
Dimensions: Holotype: shell length 40 µm, breadth 45 µm; process length 20-25 µm. Range of the English specimens (10 specimens measured): shell length 40-70 µm, breadth 35-60 µm; process length 20-28 µm. French specimens (6 specimens measured) shell length 42-60 µm, breadth 40-55 µm; process length 22-28 µm.
Original description: Gitmez, 1970, p.291-292
Central body subspherical or spherical in shape, with groups of complicated processes. In addition to the groups of processes, two single processes were observed, which are positional equivalents of the sulcus. These two single processes are foliate and furcate towards their distal ends. All the processes of each group separately rise up from the central body and are subsequently connected by bridge-like strands; near to their tips, they are foliate and fenestrate; at their tips, they are connected by a ring trabecula with denticulate edges. All the processes are solid.
The surface of the shell appears smooth and transparent; because of their transparency, identification of the processes was extremely difficult. An apical archaeopyle, slightly polygonal in shape, was seen in some of the specimens studied.
Affinities:
Gitmez, 1970, p.292: This new species of the genus Polystephanephorus differs from the previously described species in its more complicated processes. The processes are not connected proximally, as in P. urnaformis, and the branches are longer than the branches of P. calathus and P. paracalathus; they are not directed parallel to the shell surface; however the processes are linked by a ring trabecula as the other species of the genus.
P. sarjeantii is similar to Adnatosphaeridium caulleryi, but the arrangement and the manner of linkage of the processes are different.