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Muderongia pentaradiata
Muderongia pentaradiata Singh, 1983
NOW Nyktericysta. Originally Muderongia, subsequently Balmula, thirdly (and now) Nyktericysta.
Holotype: Singh, 1983, pl.43, fig.5
Locus typicus: Peace River area, Canada
Stratum typicum: Early Cenomanian
Original description: Singh, 1983, p. 127
Proximate, ceratioid, cornucavate cysts with a pentagonal body and one apical, two cingular, and two almost equal antapical horns; all five horns almost equal in length; proximal part of the cingular horns usually in line with the paracingulum and distal part directed antapically; tips of the horns with a circlet of 3 to 5 spinules; spinules pointed, 2 to 3 Ám long; periphragm smooth, membranous, and hyaline; endophragm very thin, transparent, and not clearly discernible; endophragm and periphragm presumably closely appressed; paratabulation, paracingulum, and parasulcus not indicated; archeopyle apical, type tA, usually indicated by a zigzag archeopyle suture.
Size range: Overall length including the horns 130(138)156 Ám. Holotype 135 Ám. Length of the body 50(58)67 Ám. Holotype 60 Ám. Length of the horns 35(41)54 Ám. Holotype 35 to 38 Ám. Breadth of the horns 7(10)12 Ám. Holotype 12 Ám. Specimens measured 4.
Affinities:
Singh, 1983, p. 127: Muderongia pentaradiata can be distinguished from other species of the genus Muderongia by its two antapical horns, which are almost equal in length. In most of the species assigned to Muderongia one antapical horn is reduced or absent.
M. pentaradiata differs from Muderongia asymmetrica Brideaux, 1977, whose left antapical horn is distinctly longer than the right one and the cingular horns also are unequal. Muderongia sp.1 illustrated by Vozzhennikova (1967, pl. 115, fig. 3) is comparable to M. pentaradiata in having almost equal antapical and cingular horns.
NOW Nyktericysta. Originally Muderongia, subsequently Balmula, thirdly (and now) Nyktericysta.
Holotype: Singh, 1983, pl.43, fig.5
Locus typicus: Peace River area, Canada
Stratum typicum: Early Cenomanian
Original description: Singh, 1983, p. 127
Proximate, ceratioid, cornucavate cysts with a pentagonal body and one apical, two cingular, and two almost equal antapical horns; all five horns almost equal in length; proximal part of the cingular horns usually in line with the paracingulum and distal part directed antapically; tips of the horns with a circlet of 3 to 5 spinules; spinules pointed, 2 to 3 Ám long; periphragm smooth, membranous, and hyaline; endophragm very thin, transparent, and not clearly discernible; endophragm and periphragm presumably closely appressed; paratabulation, paracingulum, and parasulcus not indicated; archeopyle apical, type tA, usually indicated by a zigzag archeopyle suture.
Size range: Overall length including the horns 130(138)156 Ám. Holotype 135 Ám. Length of the body 50(58)67 Ám. Holotype 60 Ám. Length of the horns 35(41)54 Ám. Holotype 35 to 38 Ám. Breadth of the horns 7(10)12 Ám. Holotype 12 Ám. Specimens measured 4.
Affinities:
Singh, 1983, p. 127: Muderongia pentaradiata can be distinguished from other species of the genus Muderongia by its two antapical horns, which are almost equal in length. In most of the species assigned to Muderongia one antapical horn is reduced or absent.
M. pentaradiata differs from Muderongia asymmetrica Brideaux, 1977, whose left antapical horn is distinctly longer than the right one and the cingular horns also are unequal. Muderongia sp.1 illustrated by Vozzhennikova (1967, pl. 115, fig. 3) is comparable to M. pentaradiata in having almost equal antapical and cingular horns.