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Batiacasphaera grandis
Batiacasphaera grandis, Roncaglia et al., 1999, p.299,301, fig.18, nos.1-6.
Holotype: Roncaglia et al., 1999, fig.18, no.1.
Type locality: Birch Hollow, north-flowing tributary of the Waipara River, northern Canterbury, New Zealand.
Age: late Campanian-early Maastrichtian.
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Original description: [Roncaglia et al., 1999]:
Diagnosis:
Autocyst large, subcircular to oval. Autophragm uniformly ornamented by a microreticulum that encloses small and rounded lumina.
Archeopyle apical, type tA, with zig-zag margin; operculum simple and free.
Paratabulation indicated by the archeopyle only.
Description:
Subcircular to oval autocyst with microreticulate autophragm. The microreticulum consists of relatively small, round lumina (diameter 1–1.5 µm). The muri separating the lumina are low (height: 1–2 µm) and narrow (width: c. 0.25 µm at their narrowest point). The autophragm thickness is 2–3 µm.
The paracingulum and parasulcus are not indicated.
The archeopyle is apical, type tA, with zig-zag margin; the operculum has an irregular polygonal shape; it is simple and usually free.
The paratabulation is not indicated apart from the archeopyle margin.
Dimensions:
(in µm, 15 specimens measured). holotype range Length of autocyst (without operculum) 106.7 90 (103) 118 Width of autocyst 137.1 90 (115) 145
Affinities/Discussion:
This species differs from B. imperfecta in having a regular microreticulum enveloping small, round lumina and in being bigger. Batiacasphaera grandis resembles B. kekerengensis but has smaller lumina, thinner muri, and lacks a symmetrically hexagonal operculum; furthermore, the average size of B. kekerengensis is smaller than B. grandis, although the size ranges of the two species overlap. Batiacasphaera grandis differs from B. reticulata in having a zig-zag archeopyle margin, a thicker autophragm and in being much bigger. It differs from B. asperata, B. spumosa and B. subtilis in lacking projections, granules, cones or spines on the autophragm and in being bigger. Circulodinium vermiculatum resembles B. grandis in general appearance and size, but differs in being lenticular and in having a vermiculate autophragm. Kallosphaeridium? ringnesiorum resembles the new species in general appearance and size, but differs in having an attached operculum and a high relief ornamentation consisting of club-shaped elements on the autophragm.
Holotype: Roncaglia et al., 1999, fig.18, no.1.
Type locality: Birch Hollow, north-flowing tributary of the Waipara River, northern Canterbury, New Zealand.
Age: late Campanian-early Maastrichtian.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Roncaglia et al., 1999]:
Diagnosis:
Autocyst large, subcircular to oval. Autophragm uniformly ornamented by a microreticulum that encloses small and rounded lumina.
Archeopyle apical, type tA, with zig-zag margin; operculum simple and free.
Paratabulation indicated by the archeopyle only.
Description:
Subcircular to oval autocyst with microreticulate autophragm. The microreticulum consists of relatively small, round lumina (diameter 1–1.5 µm). The muri separating the lumina are low (height: 1–2 µm) and narrow (width: c. 0.25 µm at their narrowest point). The autophragm thickness is 2–3 µm.
The paracingulum and parasulcus are not indicated.
The archeopyle is apical, type tA, with zig-zag margin; the operculum has an irregular polygonal shape; it is simple and usually free.
The paratabulation is not indicated apart from the archeopyle margin.
Dimensions:
(in µm, 15 specimens measured). holotype range Length of autocyst (without operculum) 106.7 90 (103) 118 Width of autocyst 137.1 90 (115) 145
Affinities/Discussion:
This species differs from B. imperfecta in having a regular microreticulum enveloping small, round lumina and in being bigger. Batiacasphaera grandis resembles B. kekerengensis but has smaller lumina, thinner muri, and lacks a symmetrically hexagonal operculum; furthermore, the average size of B. kekerengensis is smaller than B. grandis, although the size ranges of the two species overlap. Batiacasphaera grandis differs from B. reticulata in having a zig-zag archeopyle margin, a thicker autophragm and in being much bigger. It differs from B. asperata, B. spumosa and B. subtilis in lacking projections, granules, cones or spines on the autophragm and in being bigger. Circulodinium vermiculatum resembles B. grandis in general appearance and size, but differs in being lenticular and in having a vermiculate autophragm. Kallosphaeridium? ringnesiorum resembles the new species in general appearance and size, but differs in having an attached operculum and a high relief ornamentation consisting of club-shaped elements on the autophragm.