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Wetzeliella
From Williams et al., 2017:
[Wetzeliella, Eisenack, 1938b, p.187; Emendations: Williams and Downie, 1966b, p.182; Lentin and Williams, 1976, p.129–130; Williams, Damassa, Fensome and Guerstein in Fensome et al., 2009, p.66.
Tax. sr. syn: of Dracodinium Gocht, 1955, according to Williams, and Downie, 1966. Costa and Downie, 1979, and Bujak et al., 1980, retained Dracodinium as a separate genus.
Type species: Wetzeliella articulata, Eisenack, 1938 (fig.4)]
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[Eisenack, 1938, p. 186-187]: (Translation: LPP)
(annotated) Amongst the dinoflagellates, which form a remarkable portion of the small forms of the phosphorites, two groups are discerned: In the first we encounter forms, which do not essentially differ from the Recent species and which are easily classified in the known genera; in the other group there are species, which apparently belong in the tertiary, and which have not yet been encountered in the Cretaceous. They are principally three species with firm membranes: Wetzeliella articulata (O. Wetzel), Wetzeliella clathrata and Deflandrea phosphoritica. O. Wetzel initially classified the first species as Palaeoperidinium articulatum. Wetzeliella clathrata differs from it in the more diamond-shaped outline and the balustrade-like fusion of the marginal spines. Nevertheless, in my opinion these two species are not related to Palaeoperidinium because of the absence of tabulation or signs thereof, and because of the character of the furrows. Therefore I would suggest the name Wetzeliella to accommodate both species.
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Original description: [Eisenack 1954, p. 54]: (Translation Eisenack, 1934: Stover and Evitt, 1978, p.130)
Diagnosis: Shell more or less flattened, rhomboidal to pentagonal or also more or less oval, usually with apical horn, lateral horns on both sides and two antapical horns, all of which can be strongly reduced, without tabulation, almost always ornamented with bristles or spines. Transverse and longitudinal furrows, respectively, not determinable as flagellar groove (the former perhaps indicated sometimes). Ellipsoidal capsule present interiorly.
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Modified description:
Stover and Evitt 1978, p. 131:
Synopsis:
Cysts proximochorate, cornucavate to circumcavate, typically compressed peridinioid, with one apical, two lateral, and two antapical horns, of which some may be reduced or absent; periphragm bears isolated, normally short, tubular, rarely solid, occasionally simple branched processes; process distribution nontabular or intratabular, or both; paratabulation peridiniacean, quadra style, indicated by archeopyle only, or by intratabular and pandasuturate features; archeopyle intercalary, Type I/I.
Description:
Shape: Typically compressed peridinioid, with one apical, two antapical, and two lateral horns; outline may be slightly to greatly modified by reduction or absence of any of the horns.
Wall relationships: Cysts generally circumcavate, less commonly cornucavate; endocyst circular to broadly elliptical in outline.
Wall features: No parasutural features. Processes generally short, smooth, tubular, rarely solid, occasionally simply branched, and not connected or covered distally. Processes nontabular or in intratabular clusters, or both; intratabular clusters separated by poorly to well-determined pandasuturate features. Periphragm smooth to faintly ornamented between processes.
Paratabulation: Indicated by archeopyle only, or by archeopyle, as well as intratabular and pandasuturate features; peridiniacean paratabulation, quadra style, formula: 4`, 3a, 7``, Xc, 5```, 2````; complete paratabulation rarely expressed.
Archeopyle: Intercalary, Type I/I (2a only); archeopyle index <0.5; operculum free.
Paracingulum: Expression varies from only vaguely indicated to well-delimited by transverse alignment of processes in two parallel rows with unornamented area between; position of paracingulum may be emphasized by the presence of lateral horns.
Parasulcus: Not indicated, or expressed as a poorly delimited, commonly featureless, shallow depression on the hypocyst; flagellar scar may be present.
Size: Intermediate to large.
Affinities:
Wetzeliella differs from Rhombodinium in having processes. It differs from Kisselovia in that its processes are not connected or covered distally, and from Wilsonidium in that it has intratabular rather than parasutural features. Wetzeliella differs from Apectodinium in having more evident indications of paratabulation and generally a more distinct endocyst.
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Lentin and Vozzhennikova, 1989, p. 228:
Affinities:
The genus Gochtodinium Bujak is considered to be a junior synonym of Wetzeliella because the soleiform archaeopyle and the simple processes used to characterize Gochtodinium are considered to be intraspecific characters within the genus Wetzeliella. The species formerly in the genus Gochtodinium are here transferred to Wetzeliella.
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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.
Wetzeliella Eisenack, 1938b, emend. Williams and Downie, 1966b, emend Lentin and Williams, 1976. Wetzeliella was emended by Lentin and Williams (1976, p.129-130) as follows, Pericyst ambitus rhomboidal to pentagonal peridinioid. Apex rounded or more commonly prolonged into a short apical horn, which may be acuminate orblate or rounded distally. Two equal pericingular horns usually present, occasionally reduced or absent. Antapex prolonged into one eccentrically located antapical horn, the left, or commonly, two unequal symmetrically located antapical horns, the left always being the longer, the right being reduced or vestigial. Occasionally in specimens with a single antapical horn, this horn appears to be centrally located. From the position of the pericingular horns, the epipericyst and hypopericyst appear to be closely similar in size. Compression dorso-ventral, usually extreme. Endocyst ambitus circular to ovoidal to ellipsoidal. Rarely may be completely appressed to the pericyst when it then has the same shape. Generally only partially in contact with the pericyst, and then usually in the interhorn areas. Compression dorso-ventral, moderate to extreme. Isolated endocysts not uncommon. Pericoels. When the endocyst and pericyst are in contact in the interhorn areas, there result an apical, two cingular and one or two antapical pericoels. Alternatively, the pericoels may be united when the endocyst and pericyst are separated by a single ambital pericoel. Periphragm thin (usually less than 2 µm) and of a constant thickness. Produced into numerous nontabular simple or occasionally branched processes which are open proximally, and may be open or closed distally. Process length often reduced proportionally towards the horns and rarely exceeding 20 µm. Distally the processes may be acuminate, oblate, bifid, bifurcate or aculeate. Endophragm less than 1 μm to several microns thick. Often thicker where underlying a horn. Outer surface laevigate to granulate to verrucate; ornamentation tends to be concentrated in the vicinity of the horns. Paratabulation. Pericyst paratabulation usually indeterminate other than in the vicinity of the archeopyle. Where determinate is the typical peridinioid paratabulation of 4`, 3a, 7", 5"' , 2"'' , and 3-4s. Pericingulum produced into two pericingular horns. Commonly delineated as an indentation at the distal extremity of the pericingular horns; occasionally indicated by processes alignment. Perisulcus obscured by the processes. Flagellar pore imprints occasionally visible. Endocyst paratabulation indeterminate other than in the vicinity of the archeopyle. Archeopyle. Periarcheopyle quadra intercalary, resulting from the partial or complete detachment of the second anterior intercalary paraplate 2a. Perioperculum free or attached along the anterior parasuture Q1. Endoarcheopyle quadra intercalary, resulting from the loss of the second anterior intercalary paraplate 2a. Edoperculum usually free (but not always true). Archeopyle formula I/I (2a/2a).
Dimensions: pericyst length 42-196 µm, width 30-178 µm. Endocyst length 40-120 µm, width 28-114 µm.
[Wetzeliella, Eisenack, 1938b, p.187; Emendations: Williams and Downie, 1966b, p.182; Lentin and Williams, 1976, p.129–130; Williams, Damassa, Fensome and Guerstein in Fensome et al., 2009, p.66.
Tax. sr. syn: of Dracodinium Gocht, 1955, according to Williams, and Downie, 1966. Costa and Downie, 1979, and Bujak et al., 1980, retained Dracodinium as a separate genus.
Type species: Wetzeliella articulata, Eisenack, 1938 (fig.4)]
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[Eisenack, 1938, p. 186-187]: (Translation: LPP)
(annotated) Amongst the dinoflagellates, which form a remarkable portion of the small forms of the phosphorites, two groups are discerned: In the first we encounter forms, which do not essentially differ from the Recent species and which are easily classified in the known genera; in the other group there are species, which apparently belong in the tertiary, and which have not yet been encountered in the Cretaceous. They are principally three species with firm membranes: Wetzeliella articulata (O. Wetzel), Wetzeliella clathrata and Deflandrea phosphoritica. O. Wetzel initially classified the first species as Palaeoperidinium articulatum. Wetzeliella clathrata differs from it in the more diamond-shaped outline and the balustrade-like fusion of the marginal spines. Nevertheless, in my opinion these two species are not related to Palaeoperidinium because of the absence of tabulation or signs thereof, and because of the character of the furrows. Therefore I would suggest the name Wetzeliella to accommodate both species.
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Original description: [Eisenack 1954, p. 54]: (Translation Eisenack, 1934: Stover and Evitt, 1978, p.130)
Diagnosis: Shell more or less flattened, rhomboidal to pentagonal or also more or less oval, usually with apical horn, lateral horns on both sides and two antapical horns, all of which can be strongly reduced, without tabulation, almost always ornamented with bristles or spines. Transverse and longitudinal furrows, respectively, not determinable as flagellar groove (the former perhaps indicated sometimes). Ellipsoidal capsule present interiorly.
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Modified description:
Stover and Evitt 1978, p. 131:
Synopsis:
Cysts proximochorate, cornucavate to circumcavate, typically compressed peridinioid, with one apical, two lateral, and two antapical horns, of which some may be reduced or absent; periphragm bears isolated, normally short, tubular, rarely solid, occasionally simple branched processes; process distribution nontabular or intratabular, or both; paratabulation peridiniacean, quadra style, indicated by archeopyle only, or by intratabular and pandasuturate features; archeopyle intercalary, Type I/I.
Description:
Shape: Typically compressed peridinioid, with one apical, two antapical, and two lateral horns; outline may be slightly to greatly modified by reduction or absence of any of the horns.
Wall relationships: Cysts generally circumcavate, less commonly cornucavate; endocyst circular to broadly elliptical in outline.
Wall features: No parasutural features. Processes generally short, smooth, tubular, rarely solid, occasionally simply branched, and not connected or covered distally. Processes nontabular or in intratabular clusters, or both; intratabular clusters separated by poorly to well-determined pandasuturate features. Periphragm smooth to faintly ornamented between processes.
Paratabulation: Indicated by archeopyle only, or by archeopyle, as well as intratabular and pandasuturate features; peridiniacean paratabulation, quadra style, formula: 4`, 3a, 7``, Xc, 5```, 2````; complete paratabulation rarely expressed.
Archeopyle: Intercalary, Type I/I (2a only); archeopyle index <0.5; operculum free.
Paracingulum: Expression varies from only vaguely indicated to well-delimited by transverse alignment of processes in two parallel rows with unornamented area between; position of paracingulum may be emphasized by the presence of lateral horns.
Parasulcus: Not indicated, or expressed as a poorly delimited, commonly featureless, shallow depression on the hypocyst; flagellar scar may be present.
Size: Intermediate to large.
Affinities:
Wetzeliella differs from Rhombodinium in having processes. It differs from Kisselovia in that its processes are not connected or covered distally, and from Wilsonidium in that it has intratabular rather than parasutural features. Wetzeliella differs from Apectodinium in having more evident indications of paratabulation and generally a more distinct endocyst.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Lentin and Vozzhennikova, 1989, p. 228:
Affinities:
The genus Gochtodinium Bujak is considered to be a junior synonym of Wetzeliella because the soleiform archaeopyle and the simple processes used to characterize Gochtodinium are considered to be intraspecific characters within the genus Wetzeliella. The species formerly in the genus Gochtodinium are here transferred to Wetzeliella.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Wetzeliella Eisenack, 1938b, emend. Williams and Downie, 1966b, emend Lentin and Williams, 1976. Wetzeliella was emended by Lentin and Williams (1976, p.129-130) as follows, Pericyst ambitus rhomboidal to pentagonal peridinioid. Apex rounded or more commonly prolonged into a short apical horn, which may be acuminate orblate or rounded distally. Two equal pericingular horns usually present, occasionally reduced or absent. Antapex prolonged into one eccentrically located antapical horn, the left, or commonly, two unequal symmetrically located antapical horns, the left always being the longer, the right being reduced or vestigial. Occasionally in specimens with a single antapical horn, this horn appears to be centrally located. From the position of the pericingular horns, the epipericyst and hypopericyst appear to be closely similar in size. Compression dorso-ventral, usually extreme. Endocyst ambitus circular to ovoidal to ellipsoidal. Rarely may be completely appressed to the pericyst when it then has the same shape. Generally only partially in contact with the pericyst, and then usually in the interhorn areas. Compression dorso-ventral, moderate to extreme. Isolated endocysts not uncommon. Pericoels. When the endocyst and pericyst are in contact in the interhorn areas, there result an apical, two cingular and one or two antapical pericoels. Alternatively, the pericoels may be united when the endocyst and pericyst are separated by a single ambital pericoel. Periphragm thin (usually less than 2 µm) and of a constant thickness. Produced into numerous nontabular simple or occasionally branched processes which are open proximally, and may be open or closed distally. Process length often reduced proportionally towards the horns and rarely exceeding 20 µm. Distally the processes may be acuminate, oblate, bifid, bifurcate or aculeate. Endophragm less than 1 μm to several microns thick. Often thicker where underlying a horn. Outer surface laevigate to granulate to verrucate; ornamentation tends to be concentrated in the vicinity of the horns. Paratabulation. Pericyst paratabulation usually indeterminate other than in the vicinity of the archeopyle. Where determinate is the typical peridinioid paratabulation of 4`, 3a, 7", 5"' , 2"'' , and 3-4s. Pericingulum produced into two pericingular horns. Commonly delineated as an indentation at the distal extremity of the pericingular horns; occasionally indicated by processes alignment. Perisulcus obscured by the processes. Flagellar pore imprints occasionally visible. Endocyst paratabulation indeterminate other than in the vicinity of the archeopyle. Archeopyle. Periarcheopyle quadra intercalary, resulting from the partial or complete detachment of the second anterior intercalary paraplate 2a. Perioperculum free or attached along the anterior parasuture Q1. Endoarcheopyle quadra intercalary, resulting from the loss of the second anterior intercalary paraplate 2a. Edoperculum usually free (but not always true). Archeopyle formula I/I (2a/2a).
Dimensions: pericyst length 42-196 µm, width 30-178 µm. Endocyst length 40-120 µm, width 28-114 µm.