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Trithyrodinium druggii
Trithyrodinium druggii Stone, 1973
Holotype: Stone, 1973, pl.5, fig.18
Locus typicus: Sweetwater County, Wyoming, USA
Stratum typicum: Late Campanian
Original diagnosis: Stone, 1973, p.54
The distinctive endoblast is scabrate-granulate and exhibits apical and antapical tufts of granules. The archeopyle as observed on the endophragm is formed by the removal of three intercalary plates (1a, 2a, 3a inferred) which may become disassociated.
Original description: Stone, 1973, p.54-55
The periphram is thin (less than 1µm) and smooth. An apical horn about 28µm in length is present. Two shorter antapical horns are present. A cingulum and sulcus are not known to be present. The periblast contains a rounded endoblast. The endophram is scabrate with tufts of larger granules (ca. 1µm) on the apical and antapical ends. As observed on the endoblast, an intercalary archeopyle is formed by the removal of three plates which may become disassociated. Additional tabulation has not been observed. The range of the length of the periphragm is 95 (108) 130µm for three specimens. The width of the periphragm is about 62µm. The size range of the length of the endophragm is 58 (69) 81µm for 17 specimens.
Affinities:
Stone, 1973, p.55: Three specimen with a periphragm and endophragm were observed. The exact nature of the antapical horns is not known. The free endoblasts are abundant. T. evittii Drugg is a comparable species, but it differs in having a finely punctate endophragm and in exhibiting a cingulum on the periblast. Specimens of T. evittii have been observed to have separated opercular plates (Drugg 1971, personal communication). The species is named for Warren S. Drugg.
Holotype: Stone, 1973, pl.5, fig.18
Locus typicus: Sweetwater County, Wyoming, USA
Stratum typicum: Late Campanian
Original diagnosis: Stone, 1973, p.54
The distinctive endoblast is scabrate-granulate and exhibits apical and antapical tufts of granules. The archeopyle as observed on the endophragm is formed by the removal of three intercalary plates (1a, 2a, 3a inferred) which may become disassociated.
Original description: Stone, 1973, p.54-55
The periphram is thin (less than 1µm) and smooth. An apical horn about 28µm in length is present. Two shorter antapical horns are present. A cingulum and sulcus are not known to be present. The periblast contains a rounded endoblast. The endophram is scabrate with tufts of larger granules (ca. 1µm) on the apical and antapical ends. As observed on the endoblast, an intercalary archeopyle is formed by the removal of three plates which may become disassociated. Additional tabulation has not been observed. The range of the length of the periphragm is 95 (108) 130µm for three specimens. The width of the periphragm is about 62µm. The size range of the length of the endophragm is 58 (69) 81µm for 17 specimens.
Affinities:
Stone, 1973, p.55: Three specimen with a periphragm and endophragm were observed. The exact nature of the antapical horns is not known. The free endoblasts are abundant. T. evittii Drugg is a comparable species, but it differs in having a finely punctate endophragm and in exhibiting a cingulum on the periblast. Specimens of T. evittii have been observed to have separated opercular plates (Drugg 1971, personal communication). The species is named for Warren S. Drugg.