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Lentinia
From Fensome et al., 2019:
Lentinia, Bujak in Bujak et al., 1980, p.69.
Type: Bujak et al., 1980, pl.18, figs.7–9; text-figs.18A–F, as Lentiniaserrata.
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Original description: [Bujak in Bujak et al., 1980]:
Diagnosis:
Pericyst ambitus peridinioid, prolonged into one apical and two, more or less equal, symmetrically located antapical horns. Endocyst ambitus ovoidal to peridinioid, usually in contact with the pericyst in the precingular, cingular, and postcingular regions. Pericoels may be present or absent, but when present are cornucavate. Periphragm laevigate, chagrinate, granulate, denticulate, or rugulate; always denticulate along the paracingular margins. Endophragm laevigate or scabrate, never verrucate or tuberculate. Penitabular denticles or parasutural crests denote a paratabulation of 4`, 3a, 7``, 5```, 2````. Paraplate 1` is pentagonal and elongated anterio-posteriorly, 2` and 4` are narrower and shorter. Paraplate 3` is considerably shorter than the other apicals. Anterior intercalary paraplate 2a is hexagonal, occupies much of the dorsal epipericyst, and is broader than paraplate 4``. Paraplates 1a and 3a are considerably narrower than 2a. All the precingular paraplates are pentagonal except for 4`` which is four-sided, broad and short. Paraplate 3``` is the largest postcingular and is pentagonal, with the remaining postcingulars being four-sided. The antapical paraplates 1```` and 2```` are of approximately equal size and shape. A pericingulum is always present and is commonly indented. It is planar or very slightly helicoidal. The pericingular margins are always marked by denticulate crests. The perisulcus is indented with margins that may be delimited by crests or rows of denticles. Paratabulation has not been observed on the endocyst. The periarchaeopyle is broad hexa intercalary, resulting from the loss or displacement of paraplate 2a. Transverse archaeopyle index = 0.8 µm, longitudinal archaeopyle index = 0.5 µm, archaeopyle ratio = 0.7 µm (measurements on type species only). The endoarchaeopyle underlies the periarchaeopyle. Archaeopyle formula = I/I(2a/2a).
Affinities:
The genus Lentinia differs from Deflandrea Eisenack, 1938, in possessing the following combination of features:
1. Pericoels absent or restricted to horns, may be rarely present around an extremely narrow peripheral ambital zone.
2. Ornament on endophragm lacking; scabrate at most, usually laevigate.
3. Ornament on periphragm always includes denticles although these may be restricted to the paracingular margins.
4. The periarchaeopyle occupies most of the dorsal epipericyst, resulting in paraplates 3` and 4`` being of greatly reduced length, and paraplates 1a and 3a being of greatly reduced breadth.
5. The endoarchaeopyle is adjacent to the periarchaeopyle and has the same size and shape.
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Modified description:
Stover and Williams, 1987, p. 147:
Synopsis:
Cysts proximate, compressed peridinioid with one apical and two antapical horns; epicyst outline triangular, length of epicyst appreciably greater than that of hypocyst; generally cornucavate, occasionally bicavate; periphragm variously ornamented with subdued features, which may be arranged in intratabular clusters separated by pandasutural areas; paratabulation hexa-style peridiniacean, expressed by archeopyle and paracingulum, or by those plus intratabular features; formula: 4`, 3a, 7``, Xc, 5```, 2````; archeopyle intercalary, type l/l, paraplate 2a exceptionally large relative to width and length of epicyst, archeopyle index 0.5; operculum free.
Description:
Shape: Compressed peridinioid with an apical horn and two antapical horns.
Wall relationships: Typically cornucavate, occasionally bicavate.
Wall features: Periphragm smooth to ornamented with various features of low relief; features arranged in intratabular clusters and separated by pandasutural areas except adjacent to the paracingulum.
Archeopyle: Intercalary, type l/l (2a only), index 0.5; operculum free. Opening exceptionally large relative to length and width of epicyst.
Paratabulation: Indicated partly by archeopyle and paracingulum to completely by intratabular features in combination with the pandasutural
areas. Formula: 4`, 3a, 7``, Xc, 5```, 2```` depicts hexa-style peridiniacean paratabulation pattern.
Paracingulum: Indicated by parallel, transverse rows of denticles; area between rows slightly depressed and undivided.
Parasulcus: Indicated by interruption of paracingulum and by longitudinal depression on hypocyst, which may be defined by denticles along its
margin.
Size: Small to intermediate; about 40 to 65 µm in length.
Affinities:
Lentinia differs from Senegalinium Jain and Millepied 1973, emended Stover and Evitt 1978 and from Deflandrea Eisenack 1938 emended Lentin and Williams 1976 in having: 1. an exceptionally large archeopyle (relative to the size of the epicyst); and 2. an epicyst whose outline is triangular and whose length is appreciably greater than that of the hypocyst.
In Senegalinium the separation of the periphragm and endophragm is typically not confined to the bases of horns, and no species of Senegalinium has been described with intratabular ornamentation.
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Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Lentinia Bujak in Bujak et al., 1980. According to Bujak in Bujak et al. (1980, p.69), Lentinia has a peridinioid pericyst with one apical and two more or less equal, symmetrically located antapical horns. Endocyst generally closely appressed to pericyst, may be cornucavate. Periphragm laevigate, chagrinate, granulate, denticulate, never verrucate or tuberculate. Penitabular denticles or parasutural crests denote typical peridinioid tabulation. Pericingulum always marked by denticulate crests. Periarcheopyle isodeltaform, resulting from loss of 2a plate. Transverse archeopyle index = 0.8, longitudinal archeopyle index = 0.5, archeopyle ration = 0.7.
Lentinia, Bujak in Bujak et al., 1980, p.69.
Type: Bujak et al., 1980, pl.18, figs.7–9; text-figs.18A–F, as Lentiniaserrata.
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Original description: [Bujak in Bujak et al., 1980]:
Diagnosis:
Pericyst ambitus peridinioid, prolonged into one apical and two, more or less equal, symmetrically located antapical horns. Endocyst ambitus ovoidal to peridinioid, usually in contact with the pericyst in the precingular, cingular, and postcingular regions. Pericoels may be present or absent, but when present are cornucavate. Periphragm laevigate, chagrinate, granulate, denticulate, or rugulate; always denticulate along the paracingular margins. Endophragm laevigate or scabrate, never verrucate or tuberculate. Penitabular denticles or parasutural crests denote a paratabulation of 4`, 3a, 7``, 5```, 2````. Paraplate 1` is pentagonal and elongated anterio-posteriorly, 2` and 4` are narrower and shorter. Paraplate 3` is considerably shorter than the other apicals. Anterior intercalary paraplate 2a is hexagonal, occupies much of the dorsal epipericyst, and is broader than paraplate 4``. Paraplates 1a and 3a are considerably narrower than 2a. All the precingular paraplates are pentagonal except for 4`` which is four-sided, broad and short. Paraplate 3``` is the largest postcingular and is pentagonal, with the remaining postcingulars being four-sided. The antapical paraplates 1```` and 2```` are of approximately equal size and shape. A pericingulum is always present and is commonly indented. It is planar or very slightly helicoidal. The pericingular margins are always marked by denticulate crests. The perisulcus is indented with margins that may be delimited by crests or rows of denticles. Paratabulation has not been observed on the endocyst. The periarchaeopyle is broad hexa intercalary, resulting from the loss or displacement of paraplate 2a. Transverse archaeopyle index = 0.8 µm, longitudinal archaeopyle index = 0.5 µm, archaeopyle ratio = 0.7 µm (measurements on type species only). The endoarchaeopyle underlies the periarchaeopyle. Archaeopyle formula = I/I(2a/2a).
Affinities:
The genus Lentinia differs from Deflandrea Eisenack, 1938, in possessing the following combination of features:
1. Pericoels absent or restricted to horns, may be rarely present around an extremely narrow peripheral ambital zone.
2. Ornament on endophragm lacking; scabrate at most, usually laevigate.
3. Ornament on periphragm always includes denticles although these may be restricted to the paracingular margins.
4. The periarchaeopyle occupies most of the dorsal epipericyst, resulting in paraplates 3` and 4`` being of greatly reduced length, and paraplates 1a and 3a being of greatly reduced breadth.
5. The endoarchaeopyle is adjacent to the periarchaeopyle and has the same size and shape.
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Modified description:
Stover and Williams, 1987, p. 147:
Synopsis:
Cysts proximate, compressed peridinioid with one apical and two antapical horns; epicyst outline triangular, length of epicyst appreciably greater than that of hypocyst; generally cornucavate, occasionally bicavate; periphragm variously ornamented with subdued features, which may be arranged in intratabular clusters separated by pandasutural areas; paratabulation hexa-style peridiniacean, expressed by archeopyle and paracingulum, or by those plus intratabular features; formula: 4`, 3a, 7``, Xc, 5```, 2````; archeopyle intercalary, type l/l, paraplate 2a exceptionally large relative to width and length of epicyst, archeopyle index 0.5; operculum free.
Description:
Shape: Compressed peridinioid with an apical horn and two antapical horns.
Wall relationships: Typically cornucavate, occasionally bicavate.
Wall features: Periphragm smooth to ornamented with various features of low relief; features arranged in intratabular clusters and separated by pandasutural areas except adjacent to the paracingulum.
Archeopyle: Intercalary, type l/l (2a only), index 0.5; operculum free. Opening exceptionally large relative to length and width of epicyst.
Paratabulation: Indicated partly by archeopyle and paracingulum to completely by intratabular features in combination with the pandasutural
areas. Formula: 4`, 3a, 7``, Xc, 5```, 2```` depicts hexa-style peridiniacean paratabulation pattern.
Paracingulum: Indicated by parallel, transverse rows of denticles; area between rows slightly depressed and undivided.
Parasulcus: Indicated by interruption of paracingulum and by longitudinal depression on hypocyst, which may be defined by denticles along its
margin.
Size: Small to intermediate; about 40 to 65 µm in length.
Affinities:
Lentinia differs from Senegalinium Jain and Millepied 1973, emended Stover and Evitt 1978 and from Deflandrea Eisenack 1938 emended Lentin and Williams 1976 in having: 1. an exceptionally large archeopyle (relative to the size of the epicyst); and 2. an epicyst whose outline is triangular and whose length is appreciably greater than that of the hypocyst.
In Senegalinium the separation of the periphragm and endophragm is typically not confined to the bases of horns, and no species of Senegalinium has been described with intratabular ornamentation.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Lentinia Bujak in Bujak et al., 1980. According to Bujak in Bujak et al. (1980, p.69), Lentinia has a peridinioid pericyst with one apical and two more or less equal, symmetrically located antapical horns. Endocyst generally closely appressed to pericyst, may be cornucavate. Periphragm laevigate, chagrinate, granulate, denticulate, never verrucate or tuberculate. Penitabular denticles or parasutural crests denote typical peridinioid tabulation. Pericingulum always marked by denticulate crests. Periarcheopyle isodeltaform, resulting from loss of 2a plate. Transverse archeopyle index = 0.8, longitudinal archeopyle index = 0.5, archeopyle ration = 0.7.