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Tenua
From Williams et al., 2017:
[Tenua, Eisenack, 1958a, p. 410; Emendations: Sarjeant, 1968, p. 230–231; Pocock, 1972, p. 94; Sarjeant, 1985a, p. 93-94.
Junior homonym: Tenua Davey, 1978.
Tax. sr. syn.: Cyclonephelium, according to Sarjeant and Stover (1978, p.49) — however, Sarjeant (1985a, p.93) and Lentin and Williams (1989, p.365) retained Tenua Eisenack.
Tax. jr. syn.: Cerbia, according to Sarjeant (1985a, p.93–94) and Sarjeant (1992b, p.678) — however, Duxbury (2002, p.76,78) retained Cerbia. Duxbury (2002, p.78) considered that Tenua Eisenack may be the taxonomic senior synonym of Circulodinium.
Type species: Tenua hystrix, Eisenack, 1958 (pl.23, fig.1)]
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Original description: [Eisenack, 1958]: (Translation: Norris and Sarjeant, 1965):
Diagnosis:
Thin-walled, oval shells without tabulation or fields, which are comparatively thickly set with short, solid, rod-sharped spines.
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Emended description: [Sarjeant, 1968]:
Diagnosis:
Proximate cyst, sphaeroidal, ellipsoidal or ovoidal in shape.
Tabulation lacking: cingulum and sulcus may, however, be indicated by alignment or by absence of spines. Wall composed either of a single layer or of two layers closely appressed.
Ornamentation very variable - extremely coarse granules or tubercles: very squat wart-like spines (separate or with limited interconnection); or short rod-like spines, simple or branching, sometimes solid, always with closed tips.
Archaeopyle apical, polygonal, with slits extending posteriorly from the angles, producing a typically ragged appearance.
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Pocock, 1972:
Diagnosis:
Vesicle dorso-ventrally flattened. Archeopyle apical with offset sulcal notch and six precingular plates which are not always visible. Outline varies from more or less circular or oval without indications of horns, to rounded sub-triangular with one apical and one or two antapical horns indicated by rounded lobes or angles. Vesicle smooth or with processes, some of which may be in sutural or tabular arrangement. Tips of processes free or interconnected.
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Sarjeant, 1985:
Diagnosis:
Proximate to proximochorate cysts, penitabulate, lenticular and consisting of autophragm only. Ambitus circular, oval or rounded-pentagonal. Apex rounded or with a slight outbulge; antapex concave, rounded or with asymmetrical or symmetrical outbulges. Autophragm smooth or sculptured. Peniplates outlined by continuous or discontinuous lines of tubercles or short, solid processes; intratabular processes lacking. Paratabulation 4`, 0a, 6``, X-6c, 5-?6```, 1p, 1````, Xs.
Archaeopyle formed by loss of all apical paraplates (type "tA"), as a unit or as opercular pieces.
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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.
Tenua Eisenack, 1958a, emend. Sarjeant, 1968, emend. Pocock, 1972, emend.Sarjeant, 1985a. Emendation by Sarjeant (1985a, p.94), proximate to proximochorate cysts, penitabulate, lenticular and consisting of autophragm only. Ambitus circular, oval or rounded-pentagonal. Apex rounded or with a slight outbulge; antapex concave rounded or with two asymmetrical or symmetrical outbulges. Autophragm smooth or sculptured. Peniplates outlined by continuous or discontinuous lines of tubercles or short, solid processes. Intratabular processes lacking. Paratabulation 4`, 0a, 6", x-6c, 5-?6"' , 1p, 1"'' , xs. Archeopyle formed by loss of all apical paraplates (type tA), as a unit or as opercular pieces. Sarjeant (1985a) considered Cerbia to be a taxonomic junior synonym of Tenua.
[Tenua, Eisenack, 1958a, p. 410; Emendations: Sarjeant, 1968, p. 230–231; Pocock, 1972, p. 94; Sarjeant, 1985a, p. 93-94.
Junior homonym: Tenua Davey, 1978.
Tax. sr. syn.: Cyclonephelium, according to Sarjeant and Stover (1978, p.49) — however, Sarjeant (1985a, p.93) and Lentin and Williams (1989, p.365) retained Tenua Eisenack.
Tax. jr. syn.: Cerbia, according to Sarjeant (1985a, p.93–94) and Sarjeant (1992b, p.678) — however, Duxbury (2002, p.76,78) retained Cerbia. Duxbury (2002, p.78) considered that Tenua Eisenack may be the taxonomic senior synonym of Circulodinium.
Type species: Tenua hystrix, Eisenack, 1958 (pl.23, fig.1)]
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Eisenack, 1958]: (Translation: Norris and Sarjeant, 1965):
Diagnosis:
Thin-walled, oval shells without tabulation or fields, which are comparatively thickly set with short, solid, rod-sharped spines.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Emended description: [Sarjeant, 1968]:
Diagnosis:
Proximate cyst, sphaeroidal, ellipsoidal or ovoidal in shape.
Tabulation lacking: cingulum and sulcus may, however, be indicated by alignment or by absence of spines. Wall composed either of a single layer or of two layers closely appressed.
Ornamentation very variable - extremely coarse granules or tubercles: very squat wart-like spines (separate or with limited interconnection); or short rod-like spines, simple or branching, sometimes solid, always with closed tips.
Archaeopyle apical, polygonal, with slits extending posteriorly from the angles, producing a typically ragged appearance.
--------------------------------------
Pocock, 1972:
Diagnosis:
Vesicle dorso-ventrally flattened. Archeopyle apical with offset sulcal notch and six precingular plates which are not always visible. Outline varies from more or less circular or oval without indications of horns, to rounded sub-triangular with one apical and one or two antapical horns indicated by rounded lobes or angles. Vesicle smooth or with processes, some of which may be in sutural or tabular arrangement. Tips of processes free or interconnected.
--------------------------------------
Sarjeant, 1985:
Diagnosis:
Proximate to proximochorate cysts, penitabulate, lenticular and consisting of autophragm only. Ambitus circular, oval or rounded-pentagonal. Apex rounded or with a slight outbulge; antapex concave, rounded or with asymmetrical or symmetrical outbulges. Autophragm smooth or sculptured. Peniplates outlined by continuous or discontinuous lines of tubercles or short, solid processes; intratabular processes lacking. Paratabulation 4`, 0a, 6``, X-6c, 5-?6```, 1p, 1````, Xs.
Archaeopyle formed by loss of all apical paraplates (type "tA"), as a unit or as opercular pieces.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Tenua Eisenack, 1958a, emend. Sarjeant, 1968, emend. Pocock, 1972, emend.Sarjeant, 1985a. Emendation by Sarjeant (1985a, p.94), proximate to proximochorate cysts, penitabulate, lenticular and consisting of autophragm only. Ambitus circular, oval or rounded-pentagonal. Apex rounded or with a slight outbulge; antapex concave rounded or with two asymmetrical or symmetrical outbulges. Autophragm smooth or sculptured. Peniplates outlined by continuous or discontinuous lines of tubercles or short, solid processes. Intratabular processes lacking. Paratabulation 4`, 0a, 6", x-6c, 5-?6"' , 1p, 1"'' , xs. Archeopyle formed by loss of all apical paraplates (type tA), as a unit or as opercular pieces. Sarjeant (1985a) considered Cerbia to be a taxonomic junior synonym of Tenua.