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Yalkalpodinium scutum
Yalkalpodinium scutum, Morgan, 1980, p. 34
Holotype: Morgan, 1980, pl.31, figs.17-18
Locus typicus: Santos Oodnadatta, Australia
Stratum typicum: Late Neocomian-Late Albian
Original description: Morgan, 1980:
Cyst two-layered, subcircular to sub-pentagonal in outline; endophragm 1.5-2.5 µm thick, subcircular in outline, with or without a small apical bulge; endophragm bears ambital rugulate to vermiculate ornament 2-3 µm across in no regular pattern; wall layers closely appressed in dorsal and ventral regions but with many small elongate or irregular cavities forming an infrareticulum, size of mesh decreases towards the centre; periphragm thinner (0.5-1.0 µm), psilate on the outside, rugulate or vermiculate on the inside, so that coarse ornament is inside the ambital periphragm: Large irregular perforations to 20 µm long and 5 µm broad in periphragm located near antapex; cingulum 5-7µm broad, defined by folds or slight thickenings of periphragm, and by slight cingular bulges in the cyst outline, offset by one cingulum width at the sulcus; sulcus defined by area of wall separation 10-15 µm long and 3-4 µm broad; no other traces of tabulation; archeopyle apical. operculum free, accessory archeopyle sutures reveal six precingular plates and a sulcal notch.
Holotype: Morgan, 1980, pl.31, figs.17-18
Locus typicus: Santos Oodnadatta, Australia
Stratum typicum: Late Neocomian-Late Albian
Original description: Morgan, 1980:
Cyst two-layered, subcircular to sub-pentagonal in outline; endophragm 1.5-2.5 µm thick, subcircular in outline, with or without a small apical bulge; endophragm bears ambital rugulate to vermiculate ornament 2-3 µm across in no regular pattern; wall layers closely appressed in dorsal and ventral regions but with many small elongate or irregular cavities forming an infrareticulum, size of mesh decreases towards the centre; periphragm thinner (0.5-1.0 µm), psilate on the outside, rugulate or vermiculate on the inside, so that coarse ornament is inside the ambital periphragm: Large irregular perforations to 20 µm long and 5 µm broad in periphragm located near antapex; cingulum 5-7µm broad, defined by folds or slight thickenings of periphragm, and by slight cingular bulges in the cyst outline, offset by one cingulum width at the sulcus; sulcus defined by area of wall separation 10-15 µm long and 3-4 µm broad; no other traces of tabulation; archeopyle apical. operculum free, accessory archeopyle sutures reveal six precingular plates and a sulcal notch.