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Corrudinium eyrense
Corrudinium eyrense Clowes and Wilson, 2006, p.404, figs.4J–L,5A–C.
Holotype: Clowes and Wilson, 2006, figs.4J–L.
Age: middle Ypresian.
Original description (Clowes and Wilson, 2006)
DERIVATION OF NAME: Named after the Eyre River type locality.
HOLOTYPE: Specimen L6997/SM2572, Fig. 4J-L; sample L34/f9538, View Hill Volcanics, Upper Eyre River section, Central Canterbury, New Zealand, grid ref. L34/29407001; lower-middle Mangaorapan Stage (middle-upper Ypresian).
DESCRIPTION: Cysts of intermediate size, proximate, spherical, lack ing horns, with episome and hyposome of approximately equal size. Cyst wall single-layered and relatively thick (c. 3 μm). Archeopyle precingular, type P (3 ), relatively large, pentagonal; operculum free. Processes lacking; ornament comprising fairly prominent parasutural septa (up to 6 μm in height) with smooth or undulating crests, and lower scattered intratabular septa. Parasutural septa define an apparent gonyaulacacean paratabulation which is difficult to fullydetermine. Secondary septa are often discontinuous but sometimes form small, somewhat circular fields. Paracingulum and parasulcus expressed by parasutural septa; parasulcus often has somewhat reticulate appearance defined by secondary septa.
SIZE RANGE: Holotype 54 μm length × 51 μm breadth; range of 10 specimens 51 (55) 59 µm in maximum overall diameter.
DISTRIBUTION: Found at the type and another nearby locality (White Stream, Table 5); fairly common. The type sample, L34/f9538, contains the index dinoflagellate Wilsonidium ornatum; both localities are considered to be early Mangaorapan (middle Ypresian) in age.
REMARKS: Corrudinium eyrense differs from C. incompositum in being distinctly larger, more spherical, and more robust; it differs from C. incompositum and C. regulare in having higher parasutural and intratabular septa; and from Corrudinium otagoense in having a less densely ornamented surface. The species has some resemblance to Corrudinium obscurum but differs in having parasutural septa consistently higher than those of the intratabular ornament, whereas those of C. obscurum are of approximately similar height.
Holotype: Clowes and Wilson, 2006, figs.4J–L.
Age: middle Ypresian.
Original description (Clowes and Wilson, 2006)
DERIVATION OF NAME: Named after the Eyre River type locality.
HOLOTYPE: Specimen L6997/SM2572, Fig. 4J-L; sample L34/f9538, View Hill Volcanics, Upper Eyre River section, Central Canterbury, New Zealand, grid ref. L34/29407001; lower-middle Mangaorapan Stage (middle-upper Ypresian).
DESCRIPTION: Cysts of intermediate size, proximate, spherical, lack ing horns, with episome and hyposome of approximately equal size. Cyst wall single-layered and relatively thick (c. 3 μm). Archeopyle precingular, type P (3 ), relatively large, pentagonal; operculum free. Processes lacking; ornament comprising fairly prominent parasutural septa (up to 6 μm in height) with smooth or undulating crests, and lower scattered intratabular septa. Parasutural septa define an apparent gonyaulacacean paratabulation which is difficult to fullydetermine. Secondary septa are often discontinuous but sometimes form small, somewhat circular fields. Paracingulum and parasulcus expressed by parasutural septa; parasulcus often has somewhat reticulate appearance defined by secondary septa.
SIZE RANGE: Holotype 54 μm length × 51 μm breadth; range of 10 specimens 51 (55) 59 µm in maximum overall diameter.
DISTRIBUTION: Found at the type and another nearby locality (White Stream, Table 5); fairly common. The type sample, L34/f9538, contains the index dinoflagellate Wilsonidium ornatum; both localities are considered to be early Mangaorapan (middle Ypresian) in age.
REMARKS: Corrudinium eyrense differs from C. incompositum in being distinctly larger, more spherical, and more robust; it differs from C. incompositum and C. regulare in having higher parasutural and intratabular septa; and from Corrudinium otagoense in having a less densely ornamented surface. The species has some resemblance to Corrudinium obscurum but differs in having parasutural septa consistently higher than those of the intratabular ornament, whereas those of C. obscurum are of approximately similar height.