Back
Sverdrupiella cristata
Sverdrupiella cristata Bujak and Fisher, 1976
Taxonomic senior synonym: Sverdrupiella septentrionalis, according to Below (1987a, p.101).
Holotype: Bujak and Fisher, 1976, pl.6, fig.4; text-fig.2F
Locus typicus: Drake Point F-16, core 3721"; Queen Elizabeth Islands, arctic Canada
Stratum typicum: ?Carnian-Norian
Original diagnosis: Bujak and Fisher, 1976, p.51
Cavate to bicavate cysts with typically lateral compression, capsule spherical, ovoidal, or rhomboidal. Periphragm longer than broad, forming conical to subconical epitract which bears variably developed apical horn. Outline of hypotract asymmetrical in lateral view with smoothly concave dorsal margin and irregularly convex ventral margin formed by flared sulcal crest; second sulcal crest significantly less pronounced. Cingulum circular or laevo-rotary, defined by two distally spinose or verrucose crests. Remainder of periphragm surface bearing few scattered spines, particularly on sulcal crests. Archeopyle formed in periphragm by the loss or displacement of two, or rarely three, anterior intercalary plates which are joined along their lateral margins when attached. Opening in capsule is by subapical split.
Dimensions: Holotype, periphragm length 88 µm, periphragm thickness 62 µm, capsule length 47 µm, capsule thickness 42 µm. Observed range, periphragm length 84-102 µm, periphragm thickness 47-69 µm, capsule length 43-58 µm, capsule thickness 42-56 µm.
Taxonomic senior synonym: Sverdrupiella septentrionalis, according to Below (1987a, p.101).
Holotype: Bujak and Fisher, 1976, pl.6, fig.4; text-fig.2F
Locus typicus: Drake Point F-16, core 3721"; Queen Elizabeth Islands, arctic Canada
Stratum typicum: ?Carnian-Norian
Original diagnosis: Bujak and Fisher, 1976, p.51
Cavate to bicavate cysts with typically lateral compression, capsule spherical, ovoidal, or rhomboidal. Periphragm longer than broad, forming conical to subconical epitract which bears variably developed apical horn. Outline of hypotract asymmetrical in lateral view with smoothly concave dorsal margin and irregularly convex ventral margin formed by flared sulcal crest; second sulcal crest significantly less pronounced. Cingulum circular or laevo-rotary, defined by two distally spinose or verrucose crests. Remainder of periphragm surface bearing few scattered spines, particularly on sulcal crests. Archeopyle formed in periphragm by the loss or displacement of two, or rarely three, anterior intercalary plates which are joined along their lateral margins when attached. Opening in capsule is by subapical split.
Dimensions: Holotype, periphragm length 88 µm, periphragm thickness 62 µm, capsule length 47 µm, capsule thickness 42 µm. Observed range, periphragm length 84-102 µm, periphragm thickness 47-69 µm, capsule length 43-58 µm, capsule thickness 42-56 µm.