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Rhaetogonyaulax rhaetica
Rhaetogonyaulax rhaetica (Sarjeant, 1963b, p.353; text-figs.1–2 [left]) Loeblich Jr. and Loeblich III, 1968, p.212. Emendations: Harland et al., 1975, p.862; Fisher and van Helden, 1979, p.270; Below, 1987a, p.105–106, all as Rhaetogonyaulax rhaetica.
Originally Gonyaulax (motile stage), subsequently (and now) Rhaetogonyaulax.
Taxonomic junior synonym: Rhaetogonyaulax testacea, Rhaetogonyaulax tortuosa, and Rhaetogonyaulax uncinata, all according to Below (1987a, p.105).
Holotype: Sarjeant, 1963, text-fig.1-2(left); Harland et al., 1975, pl.110, fig.3-6
Locus typicus: Stowell Park Borehole, Northleach, Gloucestershire, England
Stratum typicum: Late Triassic
Translation Below, 1987: LPP
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP
Rhaetogonyaulax rhaetica (Sarjeant, 1963b) Loeblich Jr. and Loeblich III, 1968, emend. Harland et al., 1975, emend. Fisher and van Helden, 1979, emend. Below, 1987a. According to Below (1987, p. 105), Rhaetogonyaulax rhaetica is cornucavate, proximate, fusiform, with acuminate apex and acuminate antapex or dextral antapical horn, sometimes also with sinistral antapical bulge. Wall of dense pedium and low, spongy luxuria, with spongy surface, scabrate, punctate, microreticulate, granular, or spiny. Fine parasutures free of ornamentation. Tabulation: cop, pop, cap, 5', 4a, 7", 8c, 7-8"’, 3"”, Nrs. Archeopyle apical intercalary, PR + 1' +2' + 3' +4' + 5' + 1a + 2a + 3a + 4a. Operculum partly solvate, partly foederate, foederate pieces adnate or secate. Size: length 60-90 µm.
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Original description: Sarjeant 1963, p. 353: Gonyaulax rhaetica
Diagnosis: a species of Gonyaulax having a spindle-shaped shell, with a cover of coarse granules or very short spines, absent from the furrows. Transverse furrow broad, laevorotatory; longitudinal furrow narrow on the epi- theca but broadening considerably as it approaches the antapex. Low ridges outline the following tabulation - four apical plates (1-4'), with plate 1' elongate and situated in the anterior prolongation of the longitudinal furrow; one anterior intercalary plate (1a); six pre-equatorial plates (1-6''); six post-equatorial plates (1-6'''), plates 1''' and 2''' being reduced and quadrate; one posterior intercalary plate (1p); and one antapical plate.
Dimensions of holotype: Length 65 µm, Breath 40 µm. Estimated range (based on complete specimens and probable original size of incomplete specimens).
Emended diagnosis: Harland et al., 1975, p. 862
Cyst proximate, typic- ally spindle-shaped, unornamented or ornamented. Antapical horn may be rudimentary or well developed. Wall apparently single-layered, thin, smooth, rough, punctate, reticulate or granulate. Processes small, variable in development and distribution; random or orientated, intratabular or plate-bounding, simple and furcate. Cingulum helocoid laevorotatory, unornamented or ornamented, forming a mod- erately indented furrow; displacement may be as much as twice the cingulum width. Seven cingular plates are developed. Sulcus ornam- ented or unornamented, generally expanded on the hypotract. Cingulum and hypotractal sulcus clearly defined by plate-bounding processes or ridges; the epitractal sulcus defined by platebounding processes or by textural differences between the epitractal plate wall and the sulcal wall.
Plate sutures most readily evident where partial or complete detachment of opercular plates has occurred; hypotractal tabulation especially difficult to define. Reflected tabulation 4'-?6', 1av, 5a-?6a, 7'', 7c, 7''', 1p, 1pv, 3a, 3''''; an additional plate-area may be present in the anterior extension of plate 1a as here delineated. Archaeopyle formed initially by detachment of one or more intercalary plates, thereafter by loss of the remaining intercalariy plates, the apex as a unit, and the anterior ventral and anterior sulcal plates; cysts with archaeopyles thus show a "scalloped" edge formed by the anterior margins of the precingular plates and a deep sulcal notch resulting from the loss of the anterior sulcal plate. The median sulcal plate is often deeply indented and probably corresponds to the position of origin of the two flagella.
Dimensions: holotype (incorrectly quoted by Sarjeant 1963): Cyst length: 63.75 µm, width 37.5 µm, cingulum width 8.75 µm. Topotype and reference material size range: Length 47.5 - 92 µm, width 17.5 - 54 µm, cingulum width 5 - 13 µm.
Emended description: Below, 1987, p. 105-106
Vesicle/plate arrangement on amphiesma cop, pop, cap, 5', 4a, 7'', 8c, 7-8''', 3'''', ns; as connected dextrally with 5' and 7''. Growth of thecal plates peridinoidal.
Cyst acavate to cornu- cavate, proximate, fusiform, apex acuminate, antapex acuminate or with dextral antapical horn, sometimes also with sinistral ant- apical bulge, equatorial diameter circular; size large; wall composed of dense pedium and low, tomentose-spongy luxuria; surface spongy, scabrate, punctate, microreticular, granular, with short tubercles, spinules or nodules, ornaments evenly distributed or only intraareate or only along cingular margins; paratabulation indicated by very fine, finate ribs, and usually by limbi free from ornaments between intraareate ornamented surfaces; paratabulation formula NR PR/cop, pop, cap, NR'/5', NRa/4a, NR''/7'', NRc/Xc/8c, NR'''/7-8''', NR''''/3'''', NRs/Xs/as; cop nodular, pop horseshoe- shaped; V cap (VVL), quasi-steno omegaform camerate 1' (V), steno VII 2' (LVL), theta-deltaform camerate 3' (DL), VII 4' (DR), VII 5' (VR); fastigiate 1a (L), deltaform inverse-camerate 2a (DL) and 4a, deltaform fastigiate 3a (DDR); anteriorly geniculate VI-nE 1'' (VVL), V-nE 3'' (DL), V-nE 4'' (D), V-nE 5'' (DR) and V-nE 6'' (RVR), anteriorly linear IV-nE 2'' (L) and IV-nE 7'' (VVR); cingulum non-partite; posteriorly linear IV-nE 1''' (V), IV-nE 2''' (VL), IV-nE 4''' (DL), IV-nE 6''' (R) and IV-nE 7''' (VVR), posteriorly geniculate V-nE 3''' (L) and V-nE 5''' (DDR); VI 1'''' (VL), V 2'''' (DL) and polar VI 3'''' with hollowed sulcus; or hypocyst with 8 postcingular areae, posteriorly linear IV-nE 1''' (V), IV-nE 2''' (VL), IV-nE 4''' (DL), IV-nE 5''' (D), IV-nE 7''' (L) and IV-nE 8''' (LL)), posteriorly geniculate V-nE 3''' (L) and V-nE 6''' (DL); VI 1'''' (VL), VI 2'''' (DL) and polar VI 3'''' with hollowed sulcus; cingulum trochospiral, deeply incised, unornamented, non-partite; archaeopyle apical/anterior intercalary, PR+1'+2'+3'+4'+5'+1a+2a+3a+4a; operculum partly solvate, partly foederate, foeerate opercular pieces adnate or secate, general opercular formula 3'(s)+5'(s)+1a(s)+2a(s)+3a(s)+4a(s)+(PR+1'+2'+3'+ 4')(a/s).
Affinities:
Sarjeant 1963, p. 354
Gonyaulax rhaetica differs in its combination of symmetry and tabulation from all other described fossil species.
Originally Gonyaulax (motile stage), subsequently (and now) Rhaetogonyaulax.
Taxonomic junior synonym: Rhaetogonyaulax testacea, Rhaetogonyaulax tortuosa, and Rhaetogonyaulax uncinata, all according to Below (1987a, p.105).
Holotype: Sarjeant, 1963, text-fig.1-2(left); Harland et al., 1975, pl.110, fig.3-6
Locus typicus: Stowell Park Borehole, Northleach, Gloucestershire, England
Stratum typicum: Late Triassic
Translation Below, 1987: LPP
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP
Rhaetogonyaulax rhaetica (Sarjeant, 1963b) Loeblich Jr. and Loeblich III, 1968, emend. Harland et al., 1975, emend. Fisher and van Helden, 1979, emend. Below, 1987a. According to Below (1987, p. 105), Rhaetogonyaulax rhaetica is cornucavate, proximate, fusiform, with acuminate apex and acuminate antapex or dextral antapical horn, sometimes also with sinistral antapical bulge. Wall of dense pedium and low, spongy luxuria, with spongy surface, scabrate, punctate, microreticulate, granular, or spiny. Fine parasutures free of ornamentation. Tabulation: cop, pop, cap, 5', 4a, 7", 8c, 7-8"’, 3"”, Nrs. Archeopyle apical intercalary, PR + 1' +2' + 3' +4' + 5' + 1a + 2a + 3a + 4a. Operculum partly solvate, partly foederate, foederate pieces adnate or secate. Size: length 60-90 µm.
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Original description: Sarjeant 1963, p. 353: Gonyaulax rhaetica
Diagnosis: a species of Gonyaulax having a spindle-shaped shell, with a cover of coarse granules or very short spines, absent from the furrows. Transverse furrow broad, laevorotatory; longitudinal furrow narrow on the epi- theca but broadening considerably as it approaches the antapex. Low ridges outline the following tabulation - four apical plates (1-4'), with plate 1' elongate and situated in the anterior prolongation of the longitudinal furrow; one anterior intercalary plate (1a); six pre-equatorial plates (1-6''); six post-equatorial plates (1-6'''), plates 1''' and 2''' being reduced and quadrate; one posterior intercalary plate (1p); and one antapical plate.
Dimensions of holotype: Length 65 µm, Breath 40 µm. Estimated range (based on complete specimens and probable original size of incomplete specimens).
Emended diagnosis: Harland et al., 1975, p. 862
Cyst proximate, typic- ally spindle-shaped, unornamented or ornamented. Antapical horn may be rudimentary or well developed. Wall apparently single-layered, thin, smooth, rough, punctate, reticulate or granulate. Processes small, variable in development and distribution; random or orientated, intratabular or plate-bounding, simple and furcate. Cingulum helocoid laevorotatory, unornamented or ornamented, forming a mod- erately indented furrow; displacement may be as much as twice the cingulum width. Seven cingular plates are developed. Sulcus ornam- ented or unornamented, generally expanded on the hypotract. Cingulum and hypotractal sulcus clearly defined by plate-bounding processes or ridges; the epitractal sulcus defined by platebounding processes or by textural differences between the epitractal plate wall and the sulcal wall.
Plate sutures most readily evident where partial or complete detachment of opercular plates has occurred; hypotractal tabulation especially difficult to define. Reflected tabulation 4'-?6', 1av, 5a-?6a, 7'', 7c, 7''', 1p, 1pv, 3a, 3''''; an additional plate-area may be present in the anterior extension of plate 1a as here delineated. Archaeopyle formed initially by detachment of one or more intercalary plates, thereafter by loss of the remaining intercalariy plates, the apex as a unit, and the anterior ventral and anterior sulcal plates; cysts with archaeopyles thus show a "scalloped" edge formed by the anterior margins of the precingular plates and a deep sulcal notch resulting from the loss of the anterior sulcal plate. The median sulcal plate is often deeply indented and probably corresponds to the position of origin of the two flagella.
Dimensions: holotype (incorrectly quoted by Sarjeant 1963): Cyst length: 63.75 µm, width 37.5 µm, cingulum width 8.75 µm. Topotype and reference material size range: Length 47.5 - 92 µm, width 17.5 - 54 µm, cingulum width 5 - 13 µm.
Emended description: Below, 1987, p. 105-106
Vesicle/plate arrangement on amphiesma cop, pop, cap, 5', 4a, 7'', 8c, 7-8''', 3'''', ns; as connected dextrally with 5' and 7''. Growth of thecal plates peridinoidal.
Cyst acavate to cornu- cavate, proximate, fusiform, apex acuminate, antapex acuminate or with dextral antapical horn, sometimes also with sinistral ant- apical bulge, equatorial diameter circular; size large; wall composed of dense pedium and low, tomentose-spongy luxuria; surface spongy, scabrate, punctate, microreticular, granular, with short tubercles, spinules or nodules, ornaments evenly distributed or only intraareate or only along cingular margins; paratabulation indicated by very fine, finate ribs, and usually by limbi free from ornaments between intraareate ornamented surfaces; paratabulation formula NR PR/cop, pop, cap, NR'/5', NRa/4a, NR''/7'', NRc/Xc/8c, NR'''/7-8''', NR''''/3'''', NRs/Xs/as; cop nodular, pop horseshoe- shaped; V cap (VVL), quasi-steno omegaform camerate 1' (V), steno VII 2' (LVL), theta-deltaform camerate 3' (DL), VII 4' (DR), VII 5' (VR); fastigiate 1a (L), deltaform inverse-camerate 2a (DL) and 4a, deltaform fastigiate 3a (DDR); anteriorly geniculate VI-nE 1'' (VVL), V-nE 3'' (DL), V-nE 4'' (D), V-nE 5'' (DR) and V-nE 6'' (RVR), anteriorly linear IV-nE 2'' (L) and IV-nE 7'' (VVR); cingulum non-partite; posteriorly linear IV-nE 1''' (V), IV-nE 2''' (VL), IV-nE 4''' (DL), IV-nE 6''' (R) and IV-nE 7''' (VVR), posteriorly geniculate V-nE 3''' (L) and V-nE 5''' (DDR); VI 1'''' (VL), V 2'''' (DL) and polar VI 3'''' with hollowed sulcus; or hypocyst with 8 postcingular areae, posteriorly linear IV-nE 1''' (V), IV-nE 2''' (VL), IV-nE 4''' (DL), IV-nE 5''' (D), IV-nE 7''' (L) and IV-nE 8''' (LL)), posteriorly geniculate V-nE 3''' (L) and V-nE 6''' (DL); VI 1'''' (VL), VI 2'''' (DL) and polar VI 3'''' with hollowed sulcus; cingulum trochospiral, deeply incised, unornamented, non-partite; archaeopyle apical/anterior intercalary, PR+1'+2'+3'+4'+5'+1a+2a+3a+4a; operculum partly solvate, partly foederate, foeerate opercular pieces adnate or secate, general opercular formula 3'(s)+5'(s)+1a(s)+2a(s)+3a(s)+4a(s)+(PR+1'+2'+3'+ 4')(a/s).
Affinities:
Sarjeant 1963, p. 354
Gonyaulax rhaetica differs in its combination of symmetry and tabulation from all other described fossil species.