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Rhaetogonyaulax arctica
Rhaetogonyaulax arctica (Wiggins, 1973, p.4, pl.1, figs.1–14; pl.2, figs.1–9; text-figs.2a–d) Stover and Evitt, 1978, p.219. Emendation: Below, 1987a, p.103–105, as Rhaetogonyaulax arctica.
Originally Shublikodinium, subsequently (and now) Rhaetogonyaulax.
Taxonomic junior synonyms: Shublikodinium acanthocomum, Shublikodinium armatum, Shublikodinium setigerum, Shublikodinium spinulosum, Shublikodinium verrucosum, and (at specific rank) Shublikodinium verrucosum subsp. exsculptum, all according to Stover and Evitt (1978, p.219).
Holotype: Wiggins 1973, pl.1, fig.1-2
Paratypes: Wiggins, 1973
Locus typicus: Arctic Canada
Stratum typicum: Late Triassic
Translation Below, 1987: LPP
Original description: Wiggins 1973, p. 4: Shublikodinium arcticum
Diagnosis: Same as for the genus with the following additional description. The cyst wall of this species is characteristically covered with fine to extremely fine, low-relief grana or verrucae. The intensity of this ornamentation is variable.
The sutural tabulation of the epitract and hypotract is best known in this species, because the weak surface ornamentation has a less disguising effect on seriation patterns. The sutural trace patterns are represented by thin, shallow grooves or thin, low ridges on the epitract and hypotract surfaces, and heavy ridges along portions of the transverse furrow and posterior sulcus margins. The ridges which surround the posterior sulcus appear to be offset or set slightly away from the sutural trace of the sulcus.
Emended description: Below, 1987, p. 103-104
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-cornucavate, proximate, thickset-fusiform, biconical or divided unevenly by a very posterior cingulum into large coniform epicyst and small hemispheroid or flattened-coniform hypocyst, apically acuminate, rounded or with very broad, blunt, short apical horn, antapex rounded or with a low bulge, equatorial diameter usually circular, size small; wall composed of thick pedium and low, tomentose-spongy luxuria, often with intraareate protruberances;
surface spongy , scabrate, punctate, microreticulate, granular, with short tubercles, spinules, or nodules, ornaments evenly distributed or only intraareate or along cingular margins; paratabulation indicated by very fine finate ribs, and usually by limbi free of ornaments between intraareate ornamented spaces; 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) usually with deeply indented surface, 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 nonpartite to octopartite; posteriorly linear IV-nE 1""" (V), IV-nE 2""" (VL), IV-nE 4""" (DL), IV-nE 6""" (R) and IV-nE 7""" (VVR), posteriorly genicylate 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; sulcus broad, indented, unornamented, non-partite; archaeopyle apical/anterior intercalary, PR+1"+2"+3"+4"+5"+1a+2a+ 3a+4a; operculum partly solvate, partly foederate, foederate 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).
Originally Shublikodinium, subsequently (and now) Rhaetogonyaulax.
Taxonomic junior synonyms: Shublikodinium acanthocomum, Shublikodinium armatum, Shublikodinium setigerum, Shublikodinium spinulosum, Shublikodinium verrucosum, and (at specific rank) Shublikodinium verrucosum subsp. exsculptum, all according to Stover and Evitt (1978, p.219).
Holotype: Wiggins 1973, pl.1, fig.1-2
Paratypes: Wiggins, 1973
Locus typicus: Arctic Canada
Stratum typicum: Late Triassic
Translation Below, 1987: LPP
Original description: Wiggins 1973, p. 4: Shublikodinium arcticum
Diagnosis: Same as for the genus with the following additional description. The cyst wall of this species is characteristically covered with fine to extremely fine, low-relief grana or verrucae. The intensity of this ornamentation is variable.
The sutural tabulation of the epitract and hypotract is best known in this species, because the weak surface ornamentation has a less disguising effect on seriation patterns. The sutural trace patterns are represented by thin, shallow grooves or thin, low ridges on the epitract and hypotract surfaces, and heavy ridges along portions of the transverse furrow and posterior sulcus margins. The ridges which surround the posterior sulcus appear to be offset or set slightly away from the sutural trace of the sulcus.
Emended description: Below, 1987, p. 103-104
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-cornucavate, proximate, thickset-fusiform, biconical or divided unevenly by a very posterior cingulum into large coniform epicyst and small hemispheroid or flattened-coniform hypocyst, apically acuminate, rounded or with very broad, blunt, short apical horn, antapex rounded or with a low bulge, equatorial diameter usually circular, size small; wall composed of thick pedium and low, tomentose-spongy luxuria, often with intraareate protruberances;
surface spongy , scabrate, punctate, microreticulate, granular, with short tubercles, spinules, or nodules, ornaments evenly distributed or only intraareate or along cingular margins; paratabulation indicated by very fine finate ribs, and usually by limbi free of ornaments between intraareate ornamented spaces; 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) usually with deeply indented surface, 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 nonpartite to octopartite; posteriorly linear IV-nE 1""" (V), IV-nE 2""" (VL), IV-nE 4""" (DL), IV-nE 6""" (R) and IV-nE 7""" (VVR), posteriorly genicylate 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; sulcus broad, indented, unornamented, non-partite; archaeopyle apical/anterior intercalary, PR+1"+2"+3"+4"+5"+1a+2a+ 3a+4a; operculum partly solvate, partly foederate, foederate 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).