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Meiourogonyaulax predae
Meiourogonyaulax? predae Beju, 1971; Emendations: Drugg, 1978, p.64 and Below, 1990, p.45-46, both as Carpathodinium predae.
Now Carpathodinium. Originally Meiourogonyaulax?, subsequently Lithodinia?, thirdly (and now) Carpathodinium.
Beju, 1971, questionably included this species in Meiourogonyaulax.
Gocht, 1976, questionably transferred the species to Lithodinia Eisenack, 1935. Stover and Evitt, (1978, retained it in Meiourogonyaulax.
Holotype: Beju, 1971, pl.4, fig.4, text-fig.5
Locus typicus: Poiana Mare near Craiova, Romania
Stratum typicum: Callovian-Oxfordian
Translation Below, 1990: LPP
Original description: Beju 1971, p. 288-289
Diagnosis: Shell elongated ovoidal, epitract and hypotract almost isoradiametrical. When present, the apical horn is small and of triphid appearance. Shell wall thin, levigate. Tabulation: 4", 1a, 6"", 6c, 6""", 1p, 1"""": plate boundaries outlined by low and narrow crests. Cingulum relatively broad, slightly laevorotatory; sulcus of moderate width with a short epitractal section, broadening posteriorly. Archaeopyle formed by total or partial loss of apex.
Description: Shell wand about 1 Ám thick. When present, the apical horn is triangular in cross-section being made up by the elongated plates 1", 3", 4", but in most of the specimens seen the apex is lacking to form an archaeopyle with irregular margins. Six precingular plates are present, plates 6"" and 1" being reduced to accommodate an almost rhomboidal anterior intercalary plate. Cingulum 3-7 Ám wide, divided into six plates. Six postcingular plates are present, plate 1""" being elongated and reduced to accommodate a small posterior intercalary plate. The antapex formed by a large plate in form of a subspherical calotte which extends mostly on the ventral side.
Dimensions: Overall length: 56-74 Ám; overall width: 33-46 Ám.
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Emended description (Drugg, 1978):
Carpathodinium predae (BEJU, 1971) DRUGG, n. comb.
Pl. 1, figs. 12, 13, Pl. 2, figs. 1-6, Text-fig. 2A-F
1971 Meiourogonyaulax ? predaei BEJU, p. 288-289, PI. 4, figs. 4-7; text-fig. 5.
1974 Dinoflagellate sp. 2 of HERNGREEN & DEBOER, Pl. 6, fig. 8a-b.
Emended description: Cyst ovoidal and elongate, epicyst and hypocyst usually about equal but with the epicyst sometimes being slightly shorter than the hypocyst. A small apical projection is present. The wall is laevigate and about 1 um thick. A few scattered verrucae are sometimes present. The paratabulation is seemingly 3, 3a, 6", 6c, 6"', 1p, 1"" (see Text-fig. 2A-F). The parasutures are about 1.5 μm in height and are occasionally slightly beaded. The lacevorotatory paracingulum is about 5 um wide. Paraplates 1' and 3' are elongated and 2 is small and apparently triangular. The intercalary paraplates 1a and 3a are small and rectangular. Paraplate 2a is apparently five-sided and quite large. The archeopyle is seemingly formed by the loss of paraplates 2 and 2a. The cyst length ranges from 45 μm to 74 μm and the width ranges from 29 to 46 μm. Measurements were made on 15 specimens.
Occurrence: Figured specimens PI. 2, figs. 1-6, Couches de Passage. Figured specimen Pl. 1, figs. 12, 13, Marnes de Port-en-Bessin. All from Port-en-Bessin, Calvados, France, Bathonian, Z. zigzag Zone.
Remarks: This genus and species differs from all previously described fossil dinoflagellate cysts in paratabulation and mode of archeopyle formation. The basic paratabulation is gonyaulacid but the three intercalaries on the epicyst represent an anomalous feature. BEJU (1971) recorded this species from the Callovian and lower Oxfordian of Roumania. HERNGREEN & DeBOER (1974) record the same species (under Dinoflagellate sp. 2) from the upper Bajocian (P. parkinsoni Zone) through the lower Bathonian of the eastern Netherlands. This species is relatively rare but is fairly persistent and is a good marker for the "Middle" Jurasic. It is, however, quite small and can be easily overlooked although the distinctive outline is an aid in recognition.
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Emended description (Below, 1990) (translated from German):
Carpathodinium predae (BEJU 1971) DRUGG 1978, emend.
Plate 9, Figs. 10-20; Fig. 12
1971 Meiourogony aulax? predaei n. sp. - BEJU, p. 288; Plate 4, Figs. 4-7; Fig. 5.
1078 Carpatho dinium predae BEJU 1971) comb. Nov. & emend. - DRUGG, p. 64, plate 1, fig. 12, 13; Plate 2, Figs. 1-6; Fig. 2A-E.
Emended description:
Vesicle/plate arrangement of the dinoflagellate Amphiesma cop, pop, cap, 3', 4a, 6'', 7c, 6'", 1"", as, FM, Is, rs, ps; 1' exsert; adelopore on the suture 1'/6"; tegulation 4*, 4**, 4***, 2****, 7c, 4(*), 4(**), 3(***); growth of thecal plates in a gonyaulocoid fashion;
Zygote cyst habitus proximate, acavate, finicavate, elongate, ellipsoidal to polyhedral, epicyst conical, pyramidal, and with an apical horn, equal to or slightly smaller than the mensaform hypocyst; Wall with a thin pedium and alveolously structured luxuria, which merges distally to the tegillum or is irregularly perforated in the pole region; divided into areas by low, finite, distally smooth, distally irregularly serrate along the archaeopylene sutures, in places coarsely fenestrated, finite septa/ridges; arrangement scheme cop, pop, cap, 3', 4a, 6", 7c, 6''', 2"", as, FM, Is, rs, ps; cop tiny, round and forming an apical peg and surrounded by a small pop in a horseshoe shape, tiny rhombic to teardrop- or lanceolate cap ventrally between 2', 3' and cop; 3 apicals: small steno caroidale 1' (V) exsert, porichnion on the finis 1'/6", IX2' (VVL), X3' (VVR); 4 anterior intercalars: caroidal 1a (L), inverse camerate 2a (D), camerate 3a (DDR), caroidal 4a (R); 6 precingulate: anterior bigeniculate IV-nE 1" (VVL), anterior geniculate V-nE 2'' (LVL), anterior geniculate V-nE3'' (DL), anterior bigeniculate VI-nE 4'', Finis 3''/4''dorsal, anterior geniculate V-nE 5" (RVR), anterior geniculate V-nE 6" (VVR); cingulum left-handed spiral, lati 1c to 6c, steno 7c; 6 postcingulates: posterior linear VI-nE 1'" (VVL), posterior linear IV-nE 2'" (VL), posterior geniculate V-nE 3'" (DL), posterior linear IV-nE 4"' (D), posterior
linear IV-nE 5'" (R), posterior linear VI-nE 6'" (VVR): 2 antapics: V1"" sloping to VL and VI2"" sloping to V; sulcus areat, small, steno Vlas, steno VIFM, small IVls and Vrs, large omega-shaped VIps; archaeopyle anterior intercalary, 2a + 3a; operculum solvat, opercular plates secat, general opercular formula 2a(s) + 3a(s).
Note:
The study of the type species of the genus Carpathodinium reveals errors by BEJU (1971) and DRUGG (1978) in the reconstruction of the areation of the sulcus and the arrangement of the areas located anterior to the precingulates. PR is not grouped by three areas, as proposed by DRUGG, but only two, located dextral and sinistral to PR. The area group of the anterior intercalaries consists of four, not just three, areas. Of these, the two middle ones form the archaeopyle, not just a middorsal plate 2a, as designated by DRUGG, combined with a 2' supposedly located anterior to it. The diagnoses of the genus and the type species have been corrected accordingly. The reflected area pattern is shown in Fig. 12, the area contacts are:
PR (2', 3'),
1' (as, 1", 3', 6"),
2' (1", 2", 1a, 2a, 3a, 3', PR),
3' (1', 1", 2', PR, 3a, 4a, 5", 6"),
1" (as, c, 2", 2', 3', 1'),
2" (c, 3", 1a, 2', 1"),
3" (c, 4", 2a, 1a, 2"),
4" (c, 5", 4a, 3a, 2a, 3"),
5" (c, 6", 3', 4a, 4"),
6" (c, ac, 1', 3', 5"),
as (c, 1", 1', 6", c),
1"' (s, 1"", 2"', c),
2"' (1"', 1"", 3"', c),
3"' (2"', 1"", 2"", 4"', c),
4"' (3"', 2"", 5"', c),
5"' (4"', 2"", 6"', c),
6"' (5"', 2"", s, c),
1"" (1"', 2"', 3"', 2"", s),
2"" (1"", 3"', 4"', 5"', 6"', s).
The genus is related to Paragonyaulacysta. In addition to the generally similar habitus, the following peculiarity of the area arrangement of the apical/sulcal region is particularly striking. 1' anterior as is very small and wedged between 1" and 6". It does not protrude above the anterior level of these two areas. The finis towards 6" bears the circularly expanded porichnion, which reflects the adelopore of the theca. In anterior extension of 1' lies the large apical plate 3', which, dextral to PR, contacts the anterior intercalaries 3a and 4a, thus blocking 1' from PR and 2' (1' exsert). Sinistral to PR lies the large area 2', which, due to the blocking by 3', does not extend to 1'.
The genus Carpathodinium differs from the genera Gresslyodinium n. gen., Paragonyaulacysta, and Paraevansia n. gen. by its four anterior intercalaries, of which only 2a and 3a are removed as opercular plates. Only Evansia eschachense n. sp. is known to have four anterior intercalaries, of which 2a and 3a, and rarely 4a, are shed. However, 1' is not extruded in this species, but borders PR (insert).
Overlapping and growth mode of thecal plates are not reflected in Carpathodinium predae, but are reflected in specimen S2-1409(K4)2/8, a still undescribed species. It shows "direct overlap" of the area margins. Because of the open loophole, only the overlap in the area of the anterior intercalaries is unknown, so the following detailed tegulation scheme can be given:
R2*, R1*, F", L1*,
4**,
R1**, F**, L1*, L2**,
F****, RL1****,
R4c, R3c, R2c, R1c, Fc, L1c, L2c,
R2(*), R1(*), F(*), 1(*),
R1(**), F(**), L1(**), L2(**),
R1(***), F(***), L1(***).
The postcingulates overlap the cingulate, while the precingulates and cingulates abut each other without overlap. The arrangement of the limbi around the individual areas also shows that thecal plate growth only occurred at the overlapping edge.
Evidence:
Specimens 1394, 1395, 1409.
Now Carpathodinium. Originally Meiourogonyaulax?, subsequently Lithodinia?, thirdly (and now) Carpathodinium.
Beju, 1971, questionably included this species in Meiourogonyaulax.
Gocht, 1976, questionably transferred the species to Lithodinia Eisenack, 1935. Stover and Evitt, (1978, retained it in Meiourogonyaulax.
Holotype: Beju, 1971, pl.4, fig.4, text-fig.5
Locus typicus: Poiana Mare near Craiova, Romania
Stratum typicum: Callovian-Oxfordian
Translation Below, 1990: LPP
Original description: Beju 1971, p. 288-289
Diagnosis: Shell elongated ovoidal, epitract and hypotract almost isoradiametrical. When present, the apical horn is small and of triphid appearance. Shell wall thin, levigate. Tabulation: 4", 1a, 6"", 6c, 6""", 1p, 1"""": plate boundaries outlined by low and narrow crests. Cingulum relatively broad, slightly laevorotatory; sulcus of moderate width with a short epitractal section, broadening posteriorly. Archaeopyle formed by total or partial loss of apex.
Description: Shell wand about 1 Ám thick. When present, the apical horn is triangular in cross-section being made up by the elongated plates 1", 3", 4", but in most of the specimens seen the apex is lacking to form an archaeopyle with irregular margins. Six precingular plates are present, plates 6"" and 1" being reduced to accommodate an almost rhomboidal anterior intercalary plate. Cingulum 3-7 Ám wide, divided into six plates. Six postcingular plates are present, plate 1""" being elongated and reduced to accommodate a small posterior intercalary plate. The antapex formed by a large plate in form of a subspherical calotte which extends mostly on the ventral side.
Dimensions: Overall length: 56-74 Ám; overall width: 33-46 Ám.
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Emended description (Drugg, 1978):
Carpathodinium predae (BEJU, 1971) DRUGG, n. comb.
Pl. 1, figs. 12, 13, Pl. 2, figs. 1-6, Text-fig. 2A-F
1971 Meiourogonyaulax ? predaei BEJU, p. 288-289, PI. 4, figs. 4-7; text-fig. 5.
1974 Dinoflagellate sp. 2 of HERNGREEN & DEBOER, Pl. 6, fig. 8a-b.
Emended description: Cyst ovoidal and elongate, epicyst and hypocyst usually about equal but with the epicyst sometimes being slightly shorter than the hypocyst. A small apical projection is present. The wall is laevigate and about 1 um thick. A few scattered verrucae are sometimes present. The paratabulation is seemingly 3, 3a, 6", 6c, 6"', 1p, 1"" (see Text-fig. 2A-F). The parasutures are about 1.5 μm in height and are occasionally slightly beaded. The lacevorotatory paracingulum is about 5 um wide. Paraplates 1' and 3' are elongated and 2 is small and apparently triangular. The intercalary paraplates 1a and 3a are small and rectangular. Paraplate 2a is apparently five-sided and quite large. The archeopyle is seemingly formed by the loss of paraplates 2 and 2a. The cyst length ranges from 45 μm to 74 μm and the width ranges from 29 to 46 μm. Measurements were made on 15 specimens.
Occurrence: Figured specimens PI. 2, figs. 1-6, Couches de Passage. Figured specimen Pl. 1, figs. 12, 13, Marnes de Port-en-Bessin. All from Port-en-Bessin, Calvados, France, Bathonian, Z. zigzag Zone.
Remarks: This genus and species differs from all previously described fossil dinoflagellate cysts in paratabulation and mode of archeopyle formation. The basic paratabulation is gonyaulacid but the three intercalaries on the epicyst represent an anomalous feature. BEJU (1971) recorded this species from the Callovian and lower Oxfordian of Roumania. HERNGREEN & DeBOER (1974) record the same species (under Dinoflagellate sp. 2) from the upper Bajocian (P. parkinsoni Zone) through the lower Bathonian of the eastern Netherlands. This species is relatively rare but is fairly persistent and is a good marker for the "Middle" Jurasic. It is, however, quite small and can be easily overlooked although the distinctive outline is an aid in recognition.
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Emended description (Below, 1990) (translated from German):
Carpathodinium predae (BEJU 1971) DRUGG 1978, emend.
Plate 9, Figs. 10-20; Fig. 12
1971 Meiourogony aulax? predaei n. sp. - BEJU, p. 288; Plate 4, Figs. 4-7; Fig. 5.
1078 Carpatho dinium predae BEJU 1971) comb. Nov. & emend. - DRUGG, p. 64, plate 1, fig. 12, 13; Plate 2, Figs. 1-6; Fig. 2A-E.
Emended description:
Vesicle/plate arrangement of the dinoflagellate Amphiesma cop, pop, cap, 3', 4a, 6'', 7c, 6'", 1"", as, FM, Is, rs, ps; 1' exsert; adelopore on the suture 1'/6"; tegulation 4*, 4**, 4***, 2****, 7c, 4(*), 4(**), 3(***); growth of thecal plates in a gonyaulocoid fashion;
Zygote cyst habitus proximate, acavate, finicavate, elongate, ellipsoidal to polyhedral, epicyst conical, pyramidal, and with an apical horn, equal to or slightly smaller than the mensaform hypocyst; Wall with a thin pedium and alveolously structured luxuria, which merges distally to the tegillum or is irregularly perforated in the pole region; divided into areas by low, finite, distally smooth, distally irregularly serrate along the archaeopylene sutures, in places coarsely fenestrated, finite septa/ridges; arrangement scheme cop, pop, cap, 3', 4a, 6", 7c, 6''', 2"", as, FM, Is, rs, ps; cop tiny, round and forming an apical peg and surrounded by a small pop in a horseshoe shape, tiny rhombic to teardrop- or lanceolate cap ventrally between 2', 3' and cop; 3 apicals: small steno caroidale 1' (V) exsert, porichnion on the finis 1'/6", IX2' (VVL), X3' (VVR); 4 anterior intercalars: caroidal 1a (L), inverse camerate 2a (D), camerate 3a (DDR), caroidal 4a (R); 6 precingulate: anterior bigeniculate IV-nE 1" (VVL), anterior geniculate V-nE 2'' (LVL), anterior geniculate V-nE3'' (DL), anterior bigeniculate VI-nE 4'', Finis 3''/4''dorsal, anterior geniculate V-nE 5" (RVR), anterior geniculate V-nE 6" (VVR); cingulum left-handed spiral, lati 1c to 6c, steno 7c; 6 postcingulates: posterior linear VI-nE 1'" (VVL), posterior linear IV-nE 2'" (VL), posterior geniculate V-nE 3'" (DL), posterior linear IV-nE 4"' (D), posterior
linear IV-nE 5'" (R), posterior linear VI-nE 6'" (VVR): 2 antapics: V1"" sloping to VL and VI2"" sloping to V; sulcus areat, small, steno Vlas, steno VIFM, small IVls and Vrs, large omega-shaped VIps; archaeopyle anterior intercalary, 2a + 3a; operculum solvat, opercular plates secat, general opercular formula 2a(s) + 3a(s).
Note:
The study of the type species of the genus Carpathodinium reveals errors by BEJU (1971) and DRUGG (1978) in the reconstruction of the areation of the sulcus and the arrangement of the areas located anterior to the precingulates. PR is not grouped by three areas, as proposed by DRUGG, but only two, located dextral and sinistral to PR. The area group of the anterior intercalaries consists of four, not just three, areas. Of these, the two middle ones form the archaeopyle, not just a middorsal plate 2a, as designated by DRUGG, combined with a 2' supposedly located anterior to it. The diagnoses of the genus and the type species have been corrected accordingly. The reflected area pattern is shown in Fig. 12, the area contacts are:
PR (2', 3'),
1' (as, 1", 3', 6"),
2' (1", 2", 1a, 2a, 3a, 3', PR),
3' (1', 1", 2', PR, 3a, 4a, 5", 6"),
1" (as, c, 2", 2', 3', 1'),
2" (c, 3", 1a, 2', 1"),
3" (c, 4", 2a, 1a, 2"),
4" (c, 5", 4a, 3a, 2a, 3"),
5" (c, 6", 3', 4a, 4"),
6" (c, ac, 1', 3', 5"),
as (c, 1", 1', 6", c),
1"' (s, 1"", 2"', c),
2"' (1"', 1"", 3"', c),
3"' (2"', 1"", 2"", 4"', c),
4"' (3"', 2"", 5"', c),
5"' (4"', 2"", 6"', c),
6"' (5"', 2"", s, c),
1"" (1"', 2"', 3"', 2"", s),
2"" (1"", 3"', 4"', 5"', 6"', s).
The genus is related to Paragonyaulacysta. In addition to the generally similar habitus, the following peculiarity of the area arrangement of the apical/sulcal region is particularly striking. 1' anterior as is very small and wedged between 1" and 6". It does not protrude above the anterior level of these two areas. The finis towards 6" bears the circularly expanded porichnion, which reflects the adelopore of the theca. In anterior extension of 1' lies the large apical plate 3', which, dextral to PR, contacts the anterior intercalaries 3a and 4a, thus blocking 1' from PR and 2' (1' exsert). Sinistral to PR lies the large area 2', which, due to the blocking by 3', does not extend to 1'.
The genus Carpathodinium differs from the genera Gresslyodinium n. gen., Paragonyaulacysta, and Paraevansia n. gen. by its four anterior intercalaries, of which only 2a and 3a are removed as opercular plates. Only Evansia eschachense n. sp. is known to have four anterior intercalaries, of which 2a and 3a, and rarely 4a, are shed. However, 1' is not extruded in this species, but borders PR (insert).
Overlapping and growth mode of thecal plates are not reflected in Carpathodinium predae, but are reflected in specimen S2-1409(K4)2/8, a still undescribed species. It shows "direct overlap" of the area margins. Because of the open loophole, only the overlap in the area of the anterior intercalaries is unknown, so the following detailed tegulation scheme can be given:
R2*, R1*, F", L1*,
4**,
R1**, F**, L1*, L2**,
F****, RL1****,
R4c, R3c, R2c, R1c, Fc, L1c, L2c,
R2(*), R1(*), F(*), 1(*),
R1(**), F(**), L1(**), L2(**),
R1(***), F(***), L1(***).
The postcingulates overlap the cingulate, while the precingulates and cingulates abut each other without overlap. The arrangement of the limbi around the individual areas also shows that thecal plate growth only occurred at the overlapping edge.
Evidence:
Specimens 1394, 1395, 1409.