Back
Selenopemphix
From Williams et al., 2017:
[Selenopemphix, Benedek, 1972, p. 47 ; Emendations: Bujak in Bujak et al., 1980, p.82; Head, 1993, p.32, both as Selenopemphix.
Originally (and now) Selenopemphix, subsequently Protoperidinium subgenus Protoperidinium section Selenopemphix (name not validly published).
Head (1993, p.32) considered by implication that the acritarch genus Margosphaera Nagy, 1965, is the possible taxonomic senior synonym of this genus.
Type species: Selenopemphix nephroides, Benedek, 1972 (pl.11, fig.13)] , emend. Bujak in Bujak et al., 1980
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: {Benedek, 1972]: (Translation: Stover and Evitt 1978, p. 121-122):
Description:
Thin walled, dorso-ventrally flattened capsule without an apical process, but with two antapical projections. The outer wall of the shell is faintly granular and mostly somewhat folded. A trapeziform, laterally disposed opening penetrates the apical region.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Emended descriptions:
Stover and Evitt 1978:
Synopsis:
Cysts proximate, roundly pentagonal, commonly compressed apically-antapically, generally without an apical horn and with two antapical projections or horns; autophragm smooth or faintly ornamented; paratabulation indicated by archeopyle only, or by paracingulum and archeopyle; latter intercalary, Type I, offset laterally to left of longitudinal axis; archeopyle index 0.3 to 0.45.
Description:
Shape: Roundly pentagonal, generally without an apical horn and with two short antapical horns or projections; apical-antapical compression common.
Wall relationships: Autophragm only.
Wall features: No parasutural features. Surface smooth or ornamented with features of low relief.
Paratabulation: Indicated by archeopyle only, or by archeopyle and paracingulum.
Archeopyle: Intercalary, Type I (2a only); characteristically offset laterally to the left of the longitudinal axis; archeopyle index generally about 0.3 and consistently <0.5; operculum free.
Paracingulum: Not indicated, or expressed by low, parallel, transverse, equatorial folds or ridges, latter may be denticulate.
Parasulcus: Indicated by a shallow to moderately deep depression on the hypocyst.
Size: Intermediate to large.
Affinities:
Selenopemphix differs from Lejeunia in having a laterally offset archeopyle.
-----------------------------------------
Bujak et al., 1980:
Diagnosis:
Autocyst circular to oval in polar view, with or without a parasulcal indentation.
Dorsoventral outline peridinioid, pentagonal, or rhomboidal. Apex rounded or prolonged into an apical horn. Antapex rounded or prolonged into two, more or less symmetrically located antapical lobes or horns. The autophragm is laevigate, chagrinate, granulate, perforate, or spinate. When present, spines are usually solid and may be restricted to the paracingulum and horns, or may be present over all the autophragm.
The paratabulation is unknown other than in the vicinity of the archaeopyle. The paracingulum appears to be slightly helicoidal, with the margins denoted by crests or rows of ornament. The parasulcus is marked by an interruption of the paracingulum and also sometimes by a depression; it is broader on the hypocyst than on the epicyst.
The archaeopyle is intercalary resulting from the partial or complete detachment of the anterior intercalary paraplate 2a. It is always asymmetrically located relative to the middorsal line, with the degree of offset varying in different species. Operculum free or remaining attached along the posterior parasuture. Archaeopyle formula I (2a).
-----------------------------------------
Benedek and Sarjeant, 1981:
Diagnosis:
Cyst proximate, rotundly pentagonal in ambitus and kidney-shaped in polar view, with a broadly conical apical prominence and two rounded antapical projections, that at left longer and broader than that at right. Epitract larger than hypotract and having the form of a rounded cone. Paracingulum not indented but faintly indicated by lines on the surface: parasulcus only very faintly marked: paratabulation otherwise not indicated.
Archaeopyle formed by loss of a single, very large intercalary paraplate (Typ I), situated asymmetrically, with its longest portion to the left of the mid-dorsal line. Archaeopyle index between 0.5 and 0.7.
-----------------------------------------
Head, 1993:
Diagnosis:
Protoperidinoid dinoflagellate cysts with predominantly polar compression. Wall autophragmal or composed of several appressed wall layers. In dorsoventral view, outline broadly peridinioid, pentagonal or rhomboidal. In polar view, outline circular, oval, or reniform.
Paracingulum is planar or weakly helicoidal and margins are raised and/or bear crests and/or rows of ornament.
Parasulcus, broader on hypocyst than epicyst, is marked by a ventral interruption of paracingulum and often by a slight to deep depression.
Wall surface may be smooth, shagreenate, granulate, or perforate and may bear spines and/or low crests.
Archeopyle, formed by loss of 2a anterior intercalary paraplate, may be symmetncal or offset relative to middorsal line and has rounded angles and lacks well-developed accessory sutures. Operculum free or remains adherent along adcingular margin.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Selenopemphix Benedek, 1972, emend. Bujak in Bujak et al., 1980, emend. Head, 1993. The genus was emended by Head (1993, p.32) as follows, Protoperidinioid dinoflagellate cysts with predominantly polar compression. Wall autophragmal or composed of several appressed wall layers. In dorsoventral view, outline broadly peridinioid, pentagonal or rhomboidal. In polar view, outline circular, oval, or reniform. Paracingulum is planar or weakly helicoidal and margins are raised and/or bear crests and/or rows of ornament. Parasulcus broader on hypocyst than epicyst, is marked by a ventral interruption of paracingulum and often by a slight to deep depression. Wall surface may be smooth, shagreenate, granulate, or perforate and may bear spines and/or low crests. Archeopyle, formed by loss of 2q anterior intercalary paraplate, may be symmetrical or offset relative to middorsal line and has rounded angles and lacks well-developed accessory sutures. Operculum free or remains adherent along adcingular margin. Selenopemphix differs from Xandarodinium in having a regular circular to reniform outline in polar compression with a reduced hypocyst and epicyst, while Xandarodinium has an irregular cyst shape resulting from the extension of the wall into hollow, apparently unordered tubular processes. The archeopyle of Xandarodinium is not known according to de Verteuil and Norris (1992).
[Selenopemphix, Benedek, 1972, p. 47 ; Emendations: Bujak in Bujak et al., 1980, p.82; Head, 1993, p.32, both as Selenopemphix.
Originally (and now) Selenopemphix, subsequently Protoperidinium subgenus Protoperidinium section Selenopemphix (name not validly published).
Head (1993, p.32) considered by implication that the acritarch genus Margosphaera Nagy, 1965, is the possible taxonomic senior synonym of this genus.
Type species: Selenopemphix nephroides, Benedek, 1972 (pl.11, fig.13)] , emend. Bujak in Bujak et al., 1980
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: {Benedek, 1972]: (Translation: Stover and Evitt 1978, p. 121-122):
Description:
Thin walled, dorso-ventrally flattened capsule without an apical process, but with two antapical projections. The outer wall of the shell is faintly granular and mostly somewhat folded. A trapeziform, laterally disposed opening penetrates the apical region.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Emended descriptions:
Stover and Evitt 1978:
Synopsis:
Cysts proximate, roundly pentagonal, commonly compressed apically-antapically, generally without an apical horn and with two antapical projections or horns; autophragm smooth or faintly ornamented; paratabulation indicated by archeopyle only, or by paracingulum and archeopyle; latter intercalary, Type I, offset laterally to left of longitudinal axis; archeopyle index 0.3 to 0.45.
Description:
Shape: Roundly pentagonal, generally without an apical horn and with two short antapical horns or projections; apical-antapical compression common.
Wall relationships: Autophragm only.
Wall features: No parasutural features. Surface smooth or ornamented with features of low relief.
Paratabulation: Indicated by archeopyle only, or by archeopyle and paracingulum.
Archeopyle: Intercalary, Type I (2a only); characteristically offset laterally to the left of the longitudinal axis; archeopyle index generally about 0.3 and consistently <0.5; operculum free.
Paracingulum: Not indicated, or expressed by low, parallel, transverse, equatorial folds or ridges, latter may be denticulate.
Parasulcus: Indicated by a shallow to moderately deep depression on the hypocyst.
Size: Intermediate to large.
Affinities:
Selenopemphix differs from Lejeunia in having a laterally offset archeopyle.
-----------------------------------------
Bujak et al., 1980:
Diagnosis:
Autocyst circular to oval in polar view, with or without a parasulcal indentation.
Dorsoventral outline peridinioid, pentagonal, or rhomboidal. Apex rounded or prolonged into an apical horn. Antapex rounded or prolonged into two, more or less symmetrically located antapical lobes or horns. The autophragm is laevigate, chagrinate, granulate, perforate, or spinate. When present, spines are usually solid and may be restricted to the paracingulum and horns, or may be present over all the autophragm.
The paratabulation is unknown other than in the vicinity of the archaeopyle. The paracingulum appears to be slightly helicoidal, with the margins denoted by crests or rows of ornament. The parasulcus is marked by an interruption of the paracingulum and also sometimes by a depression; it is broader on the hypocyst than on the epicyst.
The archaeopyle is intercalary resulting from the partial or complete detachment of the anterior intercalary paraplate 2a. It is always asymmetrically located relative to the middorsal line, with the degree of offset varying in different species. Operculum free or remaining attached along the posterior parasuture. Archaeopyle formula I (2a).
-----------------------------------------
Benedek and Sarjeant, 1981:
Diagnosis:
Cyst proximate, rotundly pentagonal in ambitus and kidney-shaped in polar view, with a broadly conical apical prominence and two rounded antapical projections, that at left longer and broader than that at right. Epitract larger than hypotract and having the form of a rounded cone. Paracingulum not indented but faintly indicated by lines on the surface: parasulcus only very faintly marked: paratabulation otherwise not indicated.
Archaeopyle formed by loss of a single, very large intercalary paraplate (Typ I), situated asymmetrically, with its longest portion to the left of the mid-dorsal line. Archaeopyle index between 0.5 and 0.7.
-----------------------------------------
Head, 1993:
Diagnosis:
Protoperidinoid dinoflagellate cysts with predominantly polar compression. Wall autophragmal or composed of several appressed wall layers. In dorsoventral view, outline broadly peridinioid, pentagonal or rhomboidal. In polar view, outline circular, oval, or reniform.
Paracingulum is planar or weakly helicoidal and margins are raised and/or bear crests and/or rows of ornament.
Parasulcus, broader on hypocyst than epicyst, is marked by a ventral interruption of paracingulum and often by a slight to deep depression.
Wall surface may be smooth, shagreenate, granulate, or perforate and may bear spines and/or low crests.
Archeopyle, formed by loss of 2a anterior intercalary paraplate, may be symmetncal or offset relative to middorsal line and has rounded angles and lacks well-developed accessory sutures. Operculum free or remains adherent along adcingular margin.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Selenopemphix Benedek, 1972, emend. Bujak in Bujak et al., 1980, emend. Head, 1993. The genus was emended by Head (1993, p.32) as follows, Protoperidinioid dinoflagellate cysts with predominantly polar compression. Wall autophragmal or composed of several appressed wall layers. In dorsoventral view, outline broadly peridinioid, pentagonal or rhomboidal. In polar view, outline circular, oval, or reniform. Paracingulum is planar or weakly helicoidal and margins are raised and/or bear crests and/or rows of ornament. Parasulcus broader on hypocyst than epicyst, is marked by a ventral interruption of paracingulum and often by a slight to deep depression. Wall surface may be smooth, shagreenate, granulate, or perforate and may bear spines and/or low crests. Archeopyle, formed by loss of 2q anterior intercalary paraplate, may be symmetrical or offset relative to middorsal line and has rounded angles and lacks well-developed accessory sutures. Operculum free or remains adherent along adcingular margin. Selenopemphix differs from Xandarodinium in having a regular circular to reniform outline in polar compression with a reduced hypocyst and epicyst, while Xandarodinium has an irregular cyst shape resulting from the extension of the wall into hollow, apparently unordered tubular processes. The archeopyle of Xandarodinium is not known according to de Verteuil and Norris (1992).