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Valvaeodinium vermipellitum
Valvaeodinium vermipellitum Below, 1987
Holotype: Below, 1987, pl.24, figs.1-5; Fensome et al., 1993, p.1377, figs.1-4
Locus typicus: Clay pit of the Moorberg Brickworks, Sarstedt, Germany
Stratum typicum: Aalenian-Early Bajocian
Translation Below, 1987: Fensome et al., 1993, p.1378
Original description: Below, 1987, p.80
Arrangement of vesicles/plates on the dinoflagellate amphiesma PR, 4", 1a, 5", 6c, 5""", 1"""", ns; growth of plates peridinioid.
Cyst form proximate, acavate, spheroidal, apex somewhat acuminate or poles rounded; size small; wall composed of pedium and basally microlanate luxuria, which also forms a dense or sparse coat of short, vermiculate setules; nonareate or partially or completely areate because of the finate and intraareate arrangement of the ornament; areation formula NR PR/PR, NR"/4", NRa/1a, NR"/5", NRc/Xc, NR"""/5""", NR""""/1"""", NRs/Xs, apex undifferentiated or PR a minute, planate field; 4 apicals, steno omegaformlinteloid 1" (V), inverse-camerate 2" (LVL), VI 3" (DL), VI 4" (RVR); caroidal la (DR); 5 anteriorly geniculate precingulars, V-nE 1" (VVL), V-nE 2" (LDL), V-nE 3" (D), V-nE 4" (RDR), V-nE 5" (VR); cingulum equatorial, weakly helicoid laevorotatory, not indented, 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 32 Ám, breadth 30 Ám, thickness 30 Ám.
Remarks: Below, 1987, p.80-81 (from Fensome et al., 1993, p.1379):
This taxon developed through reduction of the limbate reticulum of Valvaeodinium spongiosum. The two species occur together in samples from the Toarcian. The fibres are no longer connected distally in Valvaeodinium vermipellitum; hence, they represent only the basal portion of the web of fibres on Valvaeodinium spongiosum. Therefore, they are undulate - and completely entangled without any orientation, perpendicular, oblique, or flatly parallel to the surface - because of their growth .... The number of setules varies. Together with mostly densely ornamented specimens, glabrous individuals also occur. If the setules form a dense coat, they are mostly very short and delicate; otherwise they are firmer. The fibres are rooted in a microlanum of very delicate, matted fibrils flatly appressed to, and fused with, the pedium, as can be seen especially well on sparsely ornamented individuals. Most individuals are uniformly ornamented. However, in the same populations there were always specimens with a finate arrangement of the setules rendering the areation either only partially, or fully, discernible. On ... [the specimen figured in Below, 1987] pl.24, figs.6-10 ... they are tightly aligned along the fines, but diffuse on intraareate regions in groups of only small numbers.
Below (1987, p.81) compared Valvaeodinium vermipellitum and Valvaeodinium vermicylindratum Below, 1987 jointly with ... older Valvaeodinium species of the Pliensbachian, Toarcian and Aalenian.
Holotype: Below, 1987, pl.24, figs.1-5; Fensome et al., 1993, p.1377, figs.1-4
Locus typicus: Clay pit of the Moorberg Brickworks, Sarstedt, Germany
Stratum typicum: Aalenian-Early Bajocian
Translation Below, 1987: Fensome et al., 1993, p.1378
Original description: Below, 1987, p.80
Arrangement of vesicles/plates on the dinoflagellate amphiesma PR, 4", 1a, 5", 6c, 5""", 1"""", ns; growth of plates peridinioid.
Cyst form proximate, acavate, spheroidal, apex somewhat acuminate or poles rounded; size small; wall composed of pedium and basally microlanate luxuria, which also forms a dense or sparse coat of short, vermiculate setules; nonareate or partially or completely areate because of the finate and intraareate arrangement of the ornament; areation formula NR PR/PR, NR"/4", NRa/1a, NR"/5", NRc/Xc, NR"""/5""", NR""""/1"""", NRs/Xs, apex undifferentiated or PR a minute, planate field; 4 apicals, steno omegaformlinteloid 1" (V), inverse-camerate 2" (LVL), VI 3" (DL), VI 4" (RVR); caroidal la (DR); 5 anteriorly geniculate precingulars, V-nE 1" (VVL), V-nE 2" (LDL), V-nE 3" (D), V-nE 4" (RDR), V-nE 5" (VR); cingulum equatorial, weakly helicoid laevorotatory, not indented, 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 32 Ám, breadth 30 Ám, thickness 30 Ám.
Remarks: Below, 1987, p.80-81 (from Fensome et al., 1993, p.1379):
This taxon developed through reduction of the limbate reticulum of Valvaeodinium spongiosum. The two species occur together in samples from the Toarcian. The fibres are no longer connected distally in Valvaeodinium vermipellitum; hence, they represent only the basal portion of the web of fibres on Valvaeodinium spongiosum. Therefore, they are undulate - and completely entangled without any orientation, perpendicular, oblique, or flatly parallel to the surface - because of their growth .... The number of setules varies. Together with mostly densely ornamented specimens, glabrous individuals also occur. If the setules form a dense coat, they are mostly very short and delicate; otherwise they are firmer. The fibres are rooted in a microlanum of very delicate, matted fibrils flatly appressed to, and fused with, the pedium, as can be seen especially well on sparsely ornamented individuals. Most individuals are uniformly ornamented. However, in the same populations there were always specimens with a finate arrangement of the setules rendering the areation either only partially, or fully, discernible. On ... [the specimen figured in Below, 1987] pl.24, figs.6-10 ... they are tightly aligned along the fines, but diffuse on intraareate regions in groups of only small numbers.
Below (1987, p.81) compared Valvaeodinium vermipellitum and Valvaeodinium vermicylindratum Below, 1987 jointly with ... older Valvaeodinium species of the Pliensbachian, Toarcian and Aalenian.