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Acanthaulax septata
Acanthaulax septata, Hultberg, 1985c, p. 104-105.
NOW Cribroperidinium. Originally Acanthaulax, subsequently (and now) Cribroperidinium (by Poulsen, 1996).
Holotype: Hultberg, 1985c, pl.1, fig.C.
Age: Late Maastrichtian-Danian.
Locus typicus: Limhamn, S Sweden
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Original description: [Hultberg, 1985, p. 104]:
Description:
Proximochorate cyst, composed of autophragm only. The surface of the autophragm is smooth. The shape of the cyst is subpolyhedral.
The cyst is covered with numerous short, solid processes with capitate process-tips. Occasional processes may be arranged in pairs, joined by septa. The processes are both nontabular, and parasutural. They are often arranged along ridges on the autophragm. These ridges may be parasutural or independent of the paratabulation. Paratabulation is incompletely expressed by parasutural ridges, and parasutural processes. The paratabulation is gonyaulacacean. Paraplates 1' to 4', and paraplates 1'' to 6'' are clearly indicated. Paraplate 6'' is distinctly triangular. Individual paracingular paraplates can not be identified on most specimens. The postcingular series consists of five or six paraplates. Possibly, paraplate 1''' is integrated in the parasulcus. Paraplate 1p has not been observed. Paraplate 1'''' is clearly indicated.
The archeopyle is precingular, type P, formed by the detachment of paraplate 3''. Operculum free.
Paracingulum is indicated by parasutural alignment of processes, and parasutural ridges on the autophragm. The individual paraplates of the paracingulum are not indicated. Parasulcus is weakly indicated by an area on the midventral surface, devoid of ornamentation, outlined by an autophragmal ridge, and parasutural processes.
Affinities: (p. 105):
Acanthaulax septata can be distinguished from A. venusta by the absence of an apical protrusion and the presence of abundant accessory ridges between parasutures. Also, no septa, connecting pairs of processes, have been described in A. venusta.
NOW Cribroperidinium. Originally Acanthaulax, subsequently (and now) Cribroperidinium (by Poulsen, 1996).
Holotype: Hultberg, 1985c, pl.1, fig.C.
Age: Late Maastrichtian-Danian.
Locus typicus: Limhamn, S Sweden
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Hultberg, 1985, p. 104]:
Description:
Proximochorate cyst, composed of autophragm only. The surface of the autophragm is smooth. The shape of the cyst is subpolyhedral.
The cyst is covered with numerous short, solid processes with capitate process-tips. Occasional processes may be arranged in pairs, joined by septa. The processes are both nontabular, and parasutural. They are often arranged along ridges on the autophragm. These ridges may be parasutural or independent of the paratabulation. Paratabulation is incompletely expressed by parasutural ridges, and parasutural processes. The paratabulation is gonyaulacacean. Paraplates 1' to 4', and paraplates 1'' to 6'' are clearly indicated. Paraplate 6'' is distinctly triangular. Individual paracingular paraplates can not be identified on most specimens. The postcingular series consists of five or six paraplates. Possibly, paraplate 1''' is integrated in the parasulcus. Paraplate 1p has not been observed. Paraplate 1'''' is clearly indicated.
The archeopyle is precingular, type P, formed by the detachment of paraplate 3''. Operculum free.
Paracingulum is indicated by parasutural alignment of processes, and parasutural ridges on the autophragm. The individual paraplates of the paracingulum are not indicated. Parasulcus is weakly indicated by an area on the midventral surface, devoid of ornamentation, outlined by an autophragmal ridge, and parasutural processes.
Affinities: (p. 105):
Acanthaulax septata can be distinguished from A. venusta by the absence of an apical protrusion and the presence of abundant accessory ridges between parasutures. Also, no septa, connecting pairs of processes, have been described in A. venusta.