Back
Hurunuia maxwellii
From Fensome et al., 2019:
Hurunuia maxwellii Wilson, 1984a, p.216–217, figs.2A–B,3–11. Holotype: Wilson, 1984a, figs.2A–B,3–5; Fensome et al., 1996, figs.1–3 — p.2221. Age: Neocomian, according to Wilson and Helby (1988).
---------------------------------------------------------------------------------------------------
Locus typicus: Kaiwara Valley, North Canterbury, New Zealand
Stratum typicum: Puaroan, Early Tithonian
Original diagnosis: Wilson, 1984, p.216
A finely reticulate Hurunuia, with a large ovoidal endocyst, a short conical epipericoel and a broad rounded hypopericoel. Parasutural ridges low, smooth. Archeopyle relatively small with a slightly zig-zag margin.
Dimensions: Holotype (with operculum): overall length 113 µm, length of endocyst 78 µm. Range of 10 specimens (all without operculum): overall length 81 (89) 103 µm, breadth 41 (52) 59 µm, length of endocyst 62 (67) 81 µm.
Original description: Wilson, 1984, p.217
The periphragm is thin, finely reticulate (lacunae up to 2 µm) and occasionally perforate (diameter of perforations up to 6 µm) The epiperiphragm is somewhat conical with a blunt apex, and the epipericoel is confined to the limits of the apical paraplate series. The hypoperiphragm has a broadly convex antapex, and the large hypopericoel sometimes extends almost to the paracingulum. Low, smooth, parasutural ridges (height up to 5 µm) are usually well developed on the dorsal surface, but are much less well defined on the ventral surface. Probable paratabulation ?pr, 4', 6'', Xc, 5''', ?0-1p, 1'''', Xs. A small subcircular area above the apical paraplate series is interpreted as a single preapical paraplate; the apical and precingular paraplates are of intermediate size; the postcingular paraplates are elongate and large; the antapical paraplate is short and broad; some specimens show evidence of a small, poorly defined posterior intercalary paraplate. The endophragm is thick (c. 6 µm), usually dark coloured, and smooth; it is in close contact with the periphragm in the central part of the pericyst. The margin of the archeopyle normally has a slightly zig-zag margin, but is often somewhat irregular. The paracingulum is fairly broad (about 8 µm) and is commonly segmented. The parasulcus is large and normally contains one small poorly defined paraplate.
Hurunuia maxwellii Wilson, 1984a, p.216–217, figs.2A–B,3–11. Holotype: Wilson, 1984a, figs.2A–B,3–5; Fensome et al., 1996, figs.1–3 — p.2221. Age: Neocomian, according to Wilson and Helby (1988).
---------------------------------------------------------------------------------------------------
Locus typicus: Kaiwara Valley, North Canterbury, New Zealand
Stratum typicum: Puaroan, Early Tithonian
Original diagnosis: Wilson, 1984, p.216
A finely reticulate Hurunuia, with a large ovoidal endocyst, a short conical epipericoel and a broad rounded hypopericoel. Parasutural ridges low, smooth. Archeopyle relatively small with a slightly zig-zag margin.
Dimensions: Holotype (with operculum): overall length 113 µm, length of endocyst 78 µm. Range of 10 specimens (all without operculum): overall length 81 (89) 103 µm, breadth 41 (52) 59 µm, length of endocyst 62 (67) 81 µm.
Original description: Wilson, 1984, p.217
The periphragm is thin, finely reticulate (lacunae up to 2 µm) and occasionally perforate (diameter of perforations up to 6 µm) The epiperiphragm is somewhat conical with a blunt apex, and the epipericoel is confined to the limits of the apical paraplate series. The hypoperiphragm has a broadly convex antapex, and the large hypopericoel sometimes extends almost to the paracingulum. Low, smooth, parasutural ridges (height up to 5 µm) are usually well developed on the dorsal surface, but are much less well defined on the ventral surface. Probable paratabulation ?pr, 4', 6'', Xc, 5''', ?0-1p, 1'''', Xs. A small subcircular area above the apical paraplate series is interpreted as a single preapical paraplate; the apical and precingular paraplates are of intermediate size; the postcingular paraplates are elongate and large; the antapical paraplate is short and broad; some specimens show evidence of a small, poorly defined posterior intercalary paraplate. The endophragm is thick (c. 6 µm), usually dark coloured, and smooth; it is in close contact with the periphragm in the central part of the pericyst. The margin of the archeopyle normally has a slightly zig-zag margin, but is often somewhat irregular. The paracingulum is fairly broad (about 8 µm) and is commonly segmented. The parasulcus is large and normally contains one small poorly defined paraplate.