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Scriniocassis weberi
Scriniocassis weberi Gocht, 1964, p.121, pl.17, figs.1a–d,2a–c,3a–c,4a–b; text-fig.39. Emendation: Below, 1990, p.36.
Taxonomic junior synonym (at specific rank): Scriniodinium (as Scriniocassis; now Scriniodinium) dictyotum subsp. osmingtonense, according to Davies (1983, p.24) — however, Jan du Chêne et al. (1986a, p.35) retained Scriniodinium dictyotum subsp. osmingtonense (as Aldorfia dictyota subsp. osmingtonensis).
Holotype: Gocht, 1964, pl.17, fig.2a-c
Locus typicus: Ziegelei Frommern, Balingen, Germany
Stratum typicum: Late Toarcian-early Bajocian
Translation Gocht, 1964, Below, 1990: LPP
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Scriniocassis weberi Gocht, 1964, emend. Below, 1990. According to emendation of Below (1990, p.36), arrangement of vesicles/plates on the dinoflagellate amphiesma cop, pop, cap, 4', 0a, 5", 7c, 6"’, 2"”, as, FM subdivided into several periflagellar areae, ls, rs, ps; pentagonal 1"” and hexagonal 2"” partiform, omegaform ps very large; tegulation as for genus; growth of thecal plates mainly along the overlapping margin (gonyaulacoid). Zygotic cyst habit proximate, holocavate, finicavate, cornucavate, endoblast spheroidal, ovaloidal, ovoidal, periblast more or less rounded-polyhedral with a conifrom to tholiform epicyst with a small horn superimposed, and a larger, longer, subconical hypocyst with a polar rim from ventral to DL along finis 1"”/2"”, equatorial section circular or slightly compressed dorsoventrally, maximal diameter at the posterior margin of the cingulum: wall two-layered, pedium and luxuriate tegillum separated by a pericoel with maximum height along the fines, but linked by an irregular variably spaced network of luxuriate muri, which may be absent at the fines, tegillum smooth, scabrate, only seldom with pores; fines marked by evaginations of tegillum forming low, plane or sheer, broad or narrow, rounded or angular embankments, sometimes absent..... epicyst rotated counterclockwise in relation to the hypocyst; PR as the apex of the apical horn undifferentiated or with an annular area pop, cop, a tubercle or peg rising on the plateau of the truncate horn with a distal horseshoe-shaped structure opening ventrally towards the cap. Archeopyle apical/precingular 3' + 2" =3"; operculum solvate, opercular pieces secate, general opercular formula 3's + 2"s + 3"s. Size: length 57-72 µm, width 53-66 µm.
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Original description: Gocht 1964, p. 121-123
Central body rounded-polygonal, inner membrane a little stronger than outer membrane. Ridges between both membranes of varying height, often constricted halfway. These ridges create an irregular, ¦ closed meshwork. The girdle zone is indicated in the outline of the shell and in the meshwork. Archaeopyle dorsal, trapezoidal, and often covering the total width of the central body. Description: The appearance of the central body is relatively constant. The inner capsule is roundish-polygonal; the rising ridges are at distinct positions higher than at other positions, thus the enveloping outer membrane shows soft, symmetrical ordered protuberances, and in between the membrane is gentle concave. In the same way the girdle zone is lifted from the central body. In a specific case the ventral side is constricted at the position of the girdle, resulting in an impression of the longitudinal furrow. The meshwork is irregularly; shape and size of the meshes vary. The ridges of the specimen shown in Fig.1, evidently a extreme variety, are high and connected only loosely to each other, which are locally (dorsally) reduced to short, winded strings. In these ridges the constrictions halfway will be more easilly recognised than in the other ridges, and also that the ridges widen towards both membranes. The girdle zone is also sometimes characterised by the structure of the meshwork, but often only faintly. The archaeopyle occupies the total width of the dorsal side. At the lower margin a thickened vaulting of the girdle zone starts, especially seen in lateral view. The middle of the girdle subsides a little again.
Affinities:
Gocht 1964, p. 121-123
Scriniocassis weberi. If the meshwork is considered, which connects the soft outer membrane with the inner capsule, the species may be compared with Valensia ovulum (=Membranilarnax ovulum), which central body is similar shaped. The outline and development of the girdlezone of S.weberi are more related to dinoflagellate cysts. Besides the archaeopyle is dorsally located, and not apically (as in Valensiella). These features have more taxonomical importance than the unstable and variable ornamentation.
Emended description (annotated): Below, 1990, p.36-37
Vesicle/plate arrangement of amphiesma cop, pop, cap, 4', 0a, 5'', 7c, 6''', 2'''', as, subdivided FM, ls, rs, ps; pentagonal 1'''' and hexagonal 2'''' partiform, omegaform ps very large. Growth of thecal plates gonyaulacoidal.
Cyst proximate, holo-, fini-, cornucavate; endoblast sphaeroidal, ovaloidal, ovoidal; periblast rounded polyhedrical, coniform to tholiform epicyst with small apical horn, hypocyst larger , approx. conical, the suture between 1'''' and 2'''' in polar position; equatorial section circular or lightly dorsoventrally flattened; wall bilayered, pedium and luxuriate tegillum separated by pericoel, but connected by luxuriate muri, that form an irregular reticulim, that may be absent along sutures. Tegillum smooth, scabrate, rarely with pores. Sutures, although sometimes not developed, marked by thickened plate-edges.
Paratabulation NR PR/cop, pop, cap, X'/4', 0a, X''/5'', Xc/7c, X'''/6''', X''''/2'''', FM subdivided, epicyst rotated counterclock- wise with respect to hypocyst.
PR undifferentiated or formed by ring-shaped plate pop, on which cop is located as a tubercle or pin, with a horseshoe-like structure that is opened ventrally towards cap, a narrow rectangle.
4 apicals: small, VI 1' (V), VII 2' (DL), isocamerate 3' (DDR), VII 4' (R);
5 precingulars: anteriorly geniculate V-nE 1'' (VL), V-nE 2'' DL), V-nE 4'' (R) and V-nE 5'' (VVR); anteriorly linear IV-nE 3'' (DDR);
cingulum weakly helicoidal, levorotatory, flat or lightly indented, divided into lati 1c-6c and steno fastigiate 7c;
6 postcingulars: posteriorly linear VI-nE 1''' (VVL), IV-nE 2''' (LVL), IV-nE 4''' (D), IV-nE 5''' (R) and V-nE 6''' (VR); posteriorly geniculate V-nE 3''' (DL);
2 antapicals partiform: V 1'''' sloping down to VL, VI 2'''' to R;
sulcus flat or lightly indented, consisting of: VI as,bean-shaped, FM undifferentiated or subdivided; small V ls and V rs, ps arrow-shaped, anteriorly narrow, posteriorly widening, and sharp between 1'''' and 2'''';
combination archaeopyle 3'+2''+3'';
operculum solvate, plates secate, formula 3'(s)+2''(s)+3''(s).
Taxonomic junior synonym (at specific rank): Scriniodinium (as Scriniocassis; now Scriniodinium) dictyotum subsp. osmingtonense, according to Davies (1983, p.24) — however, Jan du Chêne et al. (1986a, p.35) retained Scriniodinium dictyotum subsp. osmingtonense (as Aldorfia dictyota subsp. osmingtonensis).
Holotype: Gocht, 1964, pl.17, fig.2a-c
Locus typicus: Ziegelei Frommern, Balingen, Germany
Stratum typicum: Late Toarcian-early Bajocian
Translation Gocht, 1964, Below, 1990: LPP
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Scriniocassis weberi Gocht, 1964, emend. Below, 1990. According to emendation of Below (1990, p.36), arrangement of vesicles/plates on the dinoflagellate amphiesma cop, pop, cap, 4', 0a, 5", 7c, 6"’, 2"”, as, FM subdivided into several periflagellar areae, ls, rs, ps; pentagonal 1"” and hexagonal 2"” partiform, omegaform ps very large; tegulation as for genus; growth of thecal plates mainly along the overlapping margin (gonyaulacoid). Zygotic cyst habit proximate, holocavate, finicavate, cornucavate, endoblast spheroidal, ovaloidal, ovoidal, periblast more or less rounded-polyhedral with a conifrom to tholiform epicyst with a small horn superimposed, and a larger, longer, subconical hypocyst with a polar rim from ventral to DL along finis 1"”/2"”, equatorial section circular or slightly compressed dorsoventrally, maximal diameter at the posterior margin of the cingulum: wall two-layered, pedium and luxuriate tegillum separated by a pericoel with maximum height along the fines, but linked by an irregular variably spaced network of luxuriate muri, which may be absent at the fines, tegillum smooth, scabrate, only seldom with pores; fines marked by evaginations of tegillum forming low, plane or sheer, broad or narrow, rounded or angular embankments, sometimes absent..... epicyst rotated counterclockwise in relation to the hypocyst; PR as the apex of the apical horn undifferentiated or with an annular area pop, cop, a tubercle or peg rising on the plateau of the truncate horn with a distal horseshoe-shaped structure opening ventrally towards the cap. Archeopyle apical/precingular 3' + 2" =3"; operculum solvate, opercular pieces secate, general opercular formula 3's + 2"s + 3"s. Size: length 57-72 µm, width 53-66 µm.
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Original description: Gocht 1964, p. 121-123
Central body rounded-polygonal, inner membrane a little stronger than outer membrane. Ridges between both membranes of varying height, often constricted halfway. These ridges create an irregular, ¦ closed meshwork. The girdle zone is indicated in the outline of the shell and in the meshwork. Archaeopyle dorsal, trapezoidal, and often covering the total width of the central body. Description: The appearance of the central body is relatively constant. The inner capsule is roundish-polygonal; the rising ridges are at distinct positions higher than at other positions, thus the enveloping outer membrane shows soft, symmetrical ordered protuberances, and in between the membrane is gentle concave. In the same way the girdle zone is lifted from the central body. In a specific case the ventral side is constricted at the position of the girdle, resulting in an impression of the longitudinal furrow. The meshwork is irregularly; shape and size of the meshes vary. The ridges of the specimen shown in Fig.1, evidently a extreme variety, are high and connected only loosely to each other, which are locally (dorsally) reduced to short, winded strings. In these ridges the constrictions halfway will be more easilly recognised than in the other ridges, and also that the ridges widen towards both membranes. The girdle zone is also sometimes characterised by the structure of the meshwork, but often only faintly. The archaeopyle occupies the total width of the dorsal side. At the lower margin a thickened vaulting of the girdle zone starts, especially seen in lateral view. The middle of the girdle subsides a little again.
Affinities:
Gocht 1964, p. 121-123
Scriniocassis weberi. If the meshwork is considered, which connects the soft outer membrane with the inner capsule, the species may be compared with Valensia ovulum (=Membranilarnax ovulum), which central body is similar shaped. The outline and development of the girdlezone of S.weberi are more related to dinoflagellate cysts. Besides the archaeopyle is dorsally located, and not apically (as in Valensiella). These features have more taxonomical importance than the unstable and variable ornamentation.
Emended description (annotated): Below, 1990, p.36-37
Vesicle/plate arrangement of amphiesma cop, pop, cap, 4', 0a, 5'', 7c, 6''', 2'''', as, subdivided FM, ls, rs, ps; pentagonal 1'''' and hexagonal 2'''' partiform, omegaform ps very large. Growth of thecal plates gonyaulacoidal.
Cyst proximate, holo-, fini-, cornucavate; endoblast sphaeroidal, ovaloidal, ovoidal; periblast rounded polyhedrical, coniform to tholiform epicyst with small apical horn, hypocyst larger , approx. conical, the suture between 1'''' and 2'''' in polar position; equatorial section circular or lightly dorsoventrally flattened; wall bilayered, pedium and luxuriate tegillum separated by pericoel, but connected by luxuriate muri, that form an irregular reticulim, that may be absent along sutures. Tegillum smooth, scabrate, rarely with pores. Sutures, although sometimes not developed, marked by thickened plate-edges.
Paratabulation NR PR/cop, pop, cap, X'/4', 0a, X''/5'', Xc/7c, X'''/6''', X''''/2'''', FM subdivided, epicyst rotated counterclock- wise with respect to hypocyst.
PR undifferentiated or formed by ring-shaped plate pop, on which cop is located as a tubercle or pin, with a horseshoe-like structure that is opened ventrally towards cap, a narrow rectangle.
4 apicals: small, VI 1' (V), VII 2' (DL), isocamerate 3' (DDR), VII 4' (R);
5 precingulars: anteriorly geniculate V-nE 1'' (VL), V-nE 2'' DL), V-nE 4'' (R) and V-nE 5'' (VVR); anteriorly linear IV-nE 3'' (DDR);
cingulum weakly helicoidal, levorotatory, flat or lightly indented, divided into lati 1c-6c and steno fastigiate 7c;
6 postcingulars: posteriorly linear VI-nE 1''' (VVL), IV-nE 2''' (LVL), IV-nE 4''' (D), IV-nE 5''' (R) and V-nE 6''' (VR); posteriorly geniculate V-nE 3''' (DL);
2 antapicals partiform: V 1'''' sloping down to VL, VI 2'''' to R;
sulcus flat or lightly indented, consisting of: VI as,bean-shaped, FM undifferentiated or subdivided; small V ls and V rs, ps arrow-shaped, anteriorly narrow, posteriorly widening, and sharp between 1'''' and 2'''';
combination archaeopyle 3'+2''+3'';
operculum solvate, plates secate, formula 3'(s)+2''(s)+3''(s).