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Kisselovia insolens
Kisselovia? insolens Eaton, 1976
Originally Kisselovia, subsequently (and now) Kisselovia?.
Lentin and Vozzhennikova, 1989, questionably included this species in Kisselovia.
Holotype: Eaton, 1976, pl.18, fifg.2; Bujak et al., 1980, pl.11, fig.4
Locus typicus: Alum Bay, Isle of Wight, England.
Stratum typicum: Early Eocene
Original diagnosis: Eaton, 1976, p. 292
Overall outline rounded pentagonal or rounded tetragonal. Periphragm produced into five horns, one apical, two lateral and two antapical. Right antapical horn typically slightly shorter than the left. Separation of the periphragm and endophragm may be distinguishable at the base of each horn. Thick short processes are developed over the periphragm, and arranged in simulate complexes. Processes in each complex are distally united by a thick strong fenestrate membrane whose outline and area are similar to those of the underlying plate. Fenestrations in the membrane variable in size and shape (circular, subcircular or rounded polygonal). Adjacent areas of fenestrate membrane united by thick bars. The resulting outer layer has the appearance of a strong fenestrate "shell". Reflected tabulation of the form 4", 3a, 7", 5""", 2""""; archaeopyle intercalary, formed by displacement of plate 2a.
Dimensions: Holotype: overall 118 x 115 Ám. Observed range: overall 112 X 112 Ám to 148 x 134 Ám. (n = 4).
Affinities:
Eaton, 1976, p.293: Although the basic reflected tabulation in K. insolens is considered to be comparable to that of Wetzeliella Eisenack 1938 emend. Williams and Downie 1966, only the dorsal surface reflected tabulation has been precisely determined. The cingular zone is not marked by areas of fenestrate membrane; the areas of membrane over the pre- and postcingular zones are united across the cingular zone by thick bars. The presence of a strong fenestrate outer "shell" distinguishes K. insolens from described species of Kisselevia which are characterized by the presence of a relatively delicate network of distal trabeculae. K. insolens does show some overall similarity to the single specimen attributed to Wetzeliella (W.) tenuivirgula var. crassoramosa Williams and Downie 1966 in this study, but in the latter form the processes are distally united by a network of extremely thick trabeculae rather than a fenestrate "shell".
Originally Kisselovia, subsequently (and now) Kisselovia?.
Lentin and Vozzhennikova, 1989, questionably included this species in Kisselovia.
Holotype: Eaton, 1976, pl.18, fifg.2; Bujak et al., 1980, pl.11, fig.4
Locus typicus: Alum Bay, Isle of Wight, England.
Stratum typicum: Early Eocene
Original diagnosis: Eaton, 1976, p. 292
Overall outline rounded pentagonal or rounded tetragonal. Periphragm produced into five horns, one apical, two lateral and two antapical. Right antapical horn typically slightly shorter than the left. Separation of the periphragm and endophragm may be distinguishable at the base of each horn. Thick short processes are developed over the periphragm, and arranged in simulate complexes. Processes in each complex are distally united by a thick strong fenestrate membrane whose outline and area are similar to those of the underlying plate. Fenestrations in the membrane variable in size and shape (circular, subcircular or rounded polygonal). Adjacent areas of fenestrate membrane united by thick bars. The resulting outer layer has the appearance of a strong fenestrate "shell". Reflected tabulation of the form 4", 3a, 7", 5""", 2""""; archaeopyle intercalary, formed by displacement of plate 2a.
Dimensions: Holotype: overall 118 x 115 Ám. Observed range: overall 112 X 112 Ám to 148 x 134 Ám. (n = 4).
Affinities:
Eaton, 1976, p.293: Although the basic reflected tabulation in K. insolens is considered to be comparable to that of Wetzeliella Eisenack 1938 emend. Williams and Downie 1966, only the dorsal surface reflected tabulation has been precisely determined. The cingular zone is not marked by areas of fenestrate membrane; the areas of membrane over the pre- and postcingular zones are united across the cingular zone by thick bars. The presence of a strong fenestrate outer "shell" distinguishes K. insolens from described species of Kisselevia which are characterized by the presence of a relatively delicate network of distal trabeculae. K. insolens does show some overall similarity to the single specimen attributed to Wetzeliella (W.) tenuivirgula var. crassoramosa Williams and Downie 1966 in this study, but in the latter form the processes are distally united by a network of extremely thick trabeculae rather than a fenestrate "shell".