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Valvaeodinium sphaerechinatum
From Fensome et al., 2019:
Valvaeodinium sphaerechinatum Below, 1987b, p.75–76, pl.21, figs.1–6.
Holotype: Below, 1987b, pl.21, figs.2–5; Fensome et al., 1993a, figs.2–5 — p.1341.
Locus typicus: Fecocourt, Lorraine, France
Stratum typicum: Toarcian
Translation Below, 1987: Fensome et al., 1993, p. 1342
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Original description: Below, 1987, p.75-76
Arrangement of vesicles/plates on the dinoflagellate amphiesma PR, 4", la, 5", 6c, 5""", 1"""", ns; growth of plates peridinioid.
Cyst form proximate to proximochorate, acavate, spheroidal, epicyst and hypocyst of equal size; size small; wall composed of pedium and luxuria, surface microlanate, also microgranular to scabrate and with many short, cylindrical, basally somewhat wider, proximately capitate or cauliflorate appendages, which may be only peniareate or peniareate and intraareate, and are sparsely or densely scattered depending on their number, and separated by broad limbi without appendages; areation formula NR PR/PR, NR"/4", NRa/la, NR"/5", NRc/Xc, NR"""/5""", NR""""/1"""", NRs/Xs; apex undifferentiated or PR a minute, planate field; 4 apicals, steno omegaform-linteloid 1" (V), inverse-camerate 2" (LVL), VI 3" (DL), VI 4" (RVR)- caroidal 1a (DR); 5 anteriorly geniculate precingulars, V-nE 1" (WL), V-nE 2"" (LDL), V-nE 3" (D), V-nE 4" (RDR), V-nE 5" (VR); cingulum planispiral, areate, lati 1c-5c, iso 6c; 5 posteriorly linear postcingulars, IV-nE 1""" (VL), IV-nE 2""" (LDL), IV-nE 3""" (D), IV-nE 4""" (RDR), IV-nE 5""" (VR) and polar VI 1""""; sulcus nonpartite with steno quasi-trapezoidal as and narrow, steno inverse-trapezoidal posterior sector; archeopyle apical/anterior intercalary, 3" + 1a; operculum solvate, secate, general opercular formula 3"[s] + 1a[s].
Size: Holotype: length 38 Ám, breadth 36 Ám, thickness 36 Ám.
Remarks: Below, 1987, p.76
At first glance, the appendages on most specimens appear to be diffuse and rather densely distributed over the cyst surface, making a reconstruction of the areation seem impossible. However, specimens like ... [that illustrated in Below, 1987, pl.21, figs.2-6] show that the processes are either peniareate, or else both peniareate and intraareate. Also, the very broad limbi between the peniareate rows of appendages make it possible to recognize with confidence the typical Valuaeodinium areation. With this knowledge, we can then discern the same areation on many other specimens. However, on these the limbi are very narrow, and usually the appendages are less densely aligned in peniareate rows, but loosely intraareate, so that the distances between them are equal to, or even greater than, the width of the limbi on the same individual. Eventually, a completely diffuse distribution of the appendages leads to variations of the species without discernible reflection of the tabulation. Unlike Valuaeodinium armatum, Valuaeodinium koessenium, or Valvaeodinium limbafibrosum, Valvaeodinium sphaerechinatum also has cingular and sulcal appendages ([Below, 1987] pl.21, figs.2-4). The peniareate ornamentation on the cingulum usually reflects six distinctly recognizable cingular plates separated by limbi. The limbi on both cingular margins are narrow, so that also the equator of these cysts is mostly ornamented, or else the limbi are very broad (e.g.... [Below, 1987] pl.21, figs.1-4). In the latter case, two wide zones without appendages surround the equator, separated by a narrow band of cingular processes. This moves the peniareate appendages on the pre- and postcingular areae distinctly farther to the anterior/posterior, almost as in Valvaeodinium punctatum. This specimen shows once again that in taxa of the genus Valvaeodinium, the areae to the posterior of the archeopyle belong to the precingular series, and not to an intercalary series. However, the arrangement of the areae within the sulcus cannot be disentangled.
Valvaeodinium sphaerechinatum Below, 1987b, p.75–76, pl.21, figs.1–6.
Holotype: Below, 1987b, pl.21, figs.2–5; Fensome et al., 1993a, figs.2–5 — p.1341.
Locus typicus: Fecocourt, Lorraine, France
Stratum typicum: Toarcian
Translation Below, 1987: Fensome et al., 1993, p. 1342
---------------------------------------------------------------------------------------------------
Original description: Below, 1987, p.75-76
Arrangement of vesicles/plates on the dinoflagellate amphiesma PR, 4", la, 5", 6c, 5""", 1"""", ns; growth of plates peridinioid.
Cyst form proximate to proximochorate, acavate, spheroidal, epicyst and hypocyst of equal size; size small; wall composed of pedium and luxuria, surface microlanate, also microgranular to scabrate and with many short, cylindrical, basally somewhat wider, proximately capitate or cauliflorate appendages, which may be only peniareate or peniareate and intraareate, and are sparsely or densely scattered depending on their number, and separated by broad limbi without appendages; areation formula NR PR/PR, NR"/4", NRa/la, NR"/5", NRc/Xc, NR"""/5""", NR""""/1"""", NRs/Xs; apex undifferentiated or PR a minute, planate field; 4 apicals, steno omegaform-linteloid 1" (V), inverse-camerate 2" (LVL), VI 3" (DL), VI 4" (RVR)- caroidal 1a (DR); 5 anteriorly geniculate precingulars, V-nE 1" (WL), V-nE 2"" (LDL), V-nE 3" (D), V-nE 4" (RDR), V-nE 5" (VR); cingulum planispiral, areate, lati 1c-5c, iso 6c; 5 posteriorly linear postcingulars, IV-nE 1""" (VL), IV-nE 2""" (LDL), IV-nE 3""" (D), IV-nE 4""" (RDR), IV-nE 5""" (VR) and polar VI 1""""; sulcus nonpartite with steno quasi-trapezoidal as and narrow, steno inverse-trapezoidal posterior sector; archeopyle apical/anterior intercalary, 3" + 1a; operculum solvate, secate, general opercular formula 3"[s] + 1a[s].
Size: Holotype: length 38 Ám, breadth 36 Ám, thickness 36 Ám.
Remarks: Below, 1987, p.76
At first glance, the appendages on most specimens appear to be diffuse and rather densely distributed over the cyst surface, making a reconstruction of the areation seem impossible. However, specimens like ... [that illustrated in Below, 1987, pl.21, figs.2-6] show that the processes are either peniareate, or else both peniareate and intraareate. Also, the very broad limbi between the peniareate rows of appendages make it possible to recognize with confidence the typical Valuaeodinium areation. With this knowledge, we can then discern the same areation on many other specimens. However, on these the limbi are very narrow, and usually the appendages are less densely aligned in peniareate rows, but loosely intraareate, so that the distances between them are equal to, or even greater than, the width of the limbi on the same individual. Eventually, a completely diffuse distribution of the appendages leads to variations of the species without discernible reflection of the tabulation. Unlike Valuaeodinium armatum, Valuaeodinium koessenium, or Valvaeodinium limbafibrosum, Valvaeodinium sphaerechinatum also has cingular and sulcal appendages ([Below, 1987] pl.21, figs.2-4). The peniareate ornamentation on the cingulum usually reflects six distinctly recognizable cingular plates separated by limbi. The limbi on both cingular margins are narrow, so that also the equator of these cysts is mostly ornamented, or else the limbi are very broad (e.g.... [Below, 1987] pl.21, figs.1-4). In the latter case, two wide zones without appendages surround the equator, separated by a narrow band of cingular processes. This moves the peniareate appendages on the pre- and postcingular areae distinctly farther to the anterior/posterior, almost as in Valvaeodinium punctatum. This specimen shows once again that in taxa of the genus Valvaeodinium, the areae to the posterior of the archeopyle belong to the precingular series, and not to an intercalary series. However, the arrangement of the areae within the sulcus cannot be disentangled.