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Operculodinium radiculatum
Operculodinium radiculatum Smith, 1992
Quattrocchio and Sarjeant (2003, p.142) considered this species to be a possible taxonomic junior synonym of Cleistosphaeridium (now Linguladinium) bergmannii.
Holotype: Smith, 1992, figs.9,10j
Locus typicus: Cape lamb, Vega Island, James Ross Island Area, Antarctica
Stratum typicum: Late Campanian-Early Maastrichtian
Diagnosis: Smith, 1992, p. 348
A species of Operculodinium characterized by capitate processes with extensively clathrate bases; the surface sculpture is of irregular thickenings.
Description: Smith, 1992, p. 348, 351
A chorate cyst with a spherical ambitus. The process tips subtend a similar shape to that of the cyst. There is no apparent indication of a paracingulum, parasulcus or differentiated processes at the apex or antapex. The cyst body is covered in non-tabulate, partially hollow, non-fibrous, closed, capitate and recurved processes. The processes arise from several proximal stems which coalesce distally to form a single process. The length of these processes varies between 9 Ám and 18 Ám, and they are 2-4 Ám wide at the base. The body wall is irregularly thickened giving the cyst surface a coarse, scabrate appearance. The archaeopyle is type lP (3""), which is rounded and large.
Dimensions (Ám):MinMeanMax
Overall diameter555760
Specimens measured: 8
Affinities: Smith, 1992, p. 351
This taxon is assigned to Operculodinium due to the absence of differentiated apical and/or antapical processes (present in the genus Exochosphaeridium, partially hollow nonfibrous processes, and a lP archaeopyle. Operculodinium radiculatllm sp. nov. is similar to O. flucturum but can be distinguished primarily by the coarsely scabrate surface as opposed to the latter species reticulate surface and slightly larger size. Although O. flucturum can possess processes which have flared clathrate bases, in O. radiculatum this feature is developed to extremes, the proximal stems extending for two thirds the length of the process. Although within a population the length of process can vary, it is usually homogenous on each specimen.
Quattrocchio and Sarjeant (2003, p.142) considered this species to be a possible taxonomic junior synonym of Cleistosphaeridium (now Linguladinium) bergmannii.
Holotype: Smith, 1992, figs.9,10j
Locus typicus: Cape lamb, Vega Island, James Ross Island Area, Antarctica
Stratum typicum: Late Campanian-Early Maastrichtian
Diagnosis: Smith, 1992, p. 348
A species of Operculodinium characterized by capitate processes with extensively clathrate bases; the surface sculpture is of irregular thickenings.
Description: Smith, 1992, p. 348, 351
A chorate cyst with a spherical ambitus. The process tips subtend a similar shape to that of the cyst. There is no apparent indication of a paracingulum, parasulcus or differentiated processes at the apex or antapex. The cyst body is covered in non-tabulate, partially hollow, non-fibrous, closed, capitate and recurved processes. The processes arise from several proximal stems which coalesce distally to form a single process. The length of these processes varies between 9 Ám and 18 Ám, and they are 2-4 Ám wide at the base. The body wall is irregularly thickened giving the cyst surface a coarse, scabrate appearance. The archaeopyle is type lP (3""), which is rounded and large.
Dimensions (Ám):MinMeanMax
Overall diameter555760
Specimens measured: 8
Affinities: Smith, 1992, p. 351
This taxon is assigned to Operculodinium due to the absence of differentiated apical and/or antapical processes (present in the genus Exochosphaeridium, partially hollow nonfibrous processes, and a lP archaeopyle. Operculodinium radiculatllm sp. nov. is similar to O. flucturum but can be distinguished primarily by the coarsely scabrate surface as opposed to the latter species reticulate surface and slightly larger size. Although O. flucturum can possess processes which have flared clathrate bases, in O. radiculatum this feature is developed to extremes, the proximal stems extending for two thirds the length of the process. Although within a population the length of process can vary, it is usually homogenous on each specimen.