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Systematophora cretacea
Systematophora cretacea Davey, 1979
Holotype: Davey 1979b, fig. 10,13
Locus typicus: DSDP Leg 48, Hole 400A, northern Bay of Biscay, North Atlantic
Stratum typicum: Albian,
Age: Albian
Original diagnosis: Davey 1979b, p. 560
A subspherical species of Systematophora composed of a thick, densely granular wall which bears processes arranged in annular complexes. Each complex gives rise to a number of processes which may subdivide distally. Proximally the annular complexes arise from circular to rounded-triangular thickenings of the cyst wall, They vary considerably in size with the larger ones occupying the pre-, postcingular, and antapical regions; the apical and parasulcal complexes are smaller and the paracingulum is marked by a small, elongate complex which bears two simple processes. The parasulcal region may have simple processes. An apical archeopyle always appears to be developed.
Dimensions: Holotype Range
Endocyst length (operculum attached) 72 µm
Endocyst length (operculum detached) 60-64 µm
Endocyst width 69 Ám 56-69 µm
Length of processes ( maxima) 12 - 20 µm 16 (20) 24 µm
Description: Davey 1979b, p. 560
The largest annular complexes occupy the pre-, postcingular, and antapical regions and here the larger ones are membranous proximally and only divide into spines medially. In the smaller complexes the processes tend to nse directly from the proximal thickening. The size of each annular complex is related directly to the size of the paraplate, and those occupying the pre- and postcingular regions tend to be of a rounded triangular shape.
Remarks: S. cretacea sp. nov. strongly resembles S. fasciculigera Klement, 1960, which differs by having longer and more complex processes and by not having a thick granular wall. S. I alensii (Sarjeant, 1960) Downie and Sarjeant, 1964, is also similar and may, in fact, be synonymous with S. fasciculigera
Holotype: Davey 1979b, fig. 10,13
Locus typicus: DSDP Leg 48, Hole 400A, northern Bay of Biscay, North Atlantic
Stratum typicum: Albian,
Age: Albian
Original diagnosis: Davey 1979b, p. 560
A subspherical species of Systematophora composed of a thick, densely granular wall which bears processes arranged in annular complexes. Each complex gives rise to a number of processes which may subdivide distally. Proximally the annular complexes arise from circular to rounded-triangular thickenings of the cyst wall, They vary considerably in size with the larger ones occupying the pre-, postcingular, and antapical regions; the apical and parasulcal complexes are smaller and the paracingulum is marked by a small, elongate complex which bears two simple processes. The parasulcal region may have simple processes. An apical archeopyle always appears to be developed.
Dimensions: Holotype Range
Endocyst length (operculum attached) 72 µm
Endocyst length (operculum detached) 60-64 µm
Endocyst width 69 Ám 56-69 µm
Length of processes ( maxima) 12 - 20 µm 16 (20) 24 µm
Description: Davey 1979b, p. 560
The largest annular complexes occupy the pre-, postcingular, and antapical regions and here the larger ones are membranous proximally and only divide into spines medially. In the smaller complexes the processes tend to nse directly from the proximal thickening. The size of each annular complex is related directly to the size of the paraplate, and those occupying the pre- and postcingular regions tend to be of a rounded triangular shape.
Remarks: S. cretacea sp. nov. strongly resembles S. fasciculigera Klement, 1960, which differs by having longer and more complex processes and by not having a thick granular wall. S. I alensii (Sarjeant, 1960) Downie and Sarjeant, 1964, is also similar and may, in fact, be synonymous with S. fasciculigera