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Cassiculosphaeridia delicata
Cassiculasphaeridia delicata, Stover and Helby, 1987
Holotype: Stover and Helby, 1987, fig.2A-C
Locus typicus: Carnarvon Basin, Australia
Stratum typicum: Berriasian
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Original description: [Stover and Helby, 1987, p. 103]:
Description:
Cysts proximate and subspherical.
Autophragm smooth, about 1 µm or less in thickness, and overlain by an ectophragm in the form of a perfect to imperfect reticulum. Reticulum usually complete and well developed, and may be confined within pandasutural bands 3 (Fig.2C,H). Muri narrow (1.5 µm or less), variable in thickness, 2-6 µm in height, outlining circular to polygonal lumina about 2-8 µm in maximum diameter; most lumina less than 5 µm in diameter. Muri become lower and less well defined away from the parasutures (particularly those at the archeopyle, the paracingulum and the antapex); clarity of reticulation diminishes gradually, and may be indistinguishable on the central portions of the paraplates.
Archeopyle apical, type [tA].
Paratabulation generally poorly expressed by the parasutural reticulate bands (Fig.2A,C,F,H) and the archeopyle. Paratabulation formula interpreted as ?pr, 4", 6"", Xc, 5""", and 1"""". Small subcircular area at the apex (Fig.2A,F) tentatively interpreted as a preapical paraplate. Paracingulum defined by a reticulate, equatorial ridge. Parasulcus rarely identified.
Variability: The development of reticulation is the major variable within and between populations of C. delicata. The holotype (Fig.2A-C) represents most extreme pandasutural restriction of the reticulation (but best exhibits the salient features of the species), one paratype (Fig.2G,H) exhibits average development of the reticulation, while another (Fig.2D,E) is representative of specimens, in which the reticulation entirely covers most paraplate surfaces.
Dimensions:
Fifty specimens measured: 53(79)105 µm in diameter.
Affinities:
Cassiculosphaeridia delicata is similar to C. reticulata Davey 1969 but is distinguished in being larger (approximately twice as large) and in lacking membranous crests arising from the muri. Although C. delicata is similar in size to C. magna Davey 1974, it has a thinner, more delicate reticulation.
Holotype: Stover and Helby, 1987, fig.2A-C
Locus typicus: Carnarvon Basin, Australia
Stratum typicum: Berriasian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Stover and Helby, 1987, p. 103]:
Description:
Cysts proximate and subspherical.
Autophragm smooth, about 1 µm or less in thickness, and overlain by an ectophragm in the form of a perfect to imperfect reticulum. Reticulum usually complete and well developed, and may be confined within pandasutural bands 3 (Fig.2C,H). Muri narrow (1.5 µm or less), variable in thickness, 2-6 µm in height, outlining circular to polygonal lumina about 2-8 µm in maximum diameter; most lumina less than 5 µm in diameter. Muri become lower and less well defined away from the parasutures (particularly those at the archeopyle, the paracingulum and the antapex); clarity of reticulation diminishes gradually, and may be indistinguishable on the central portions of the paraplates.
Archeopyle apical, type [tA].
Paratabulation generally poorly expressed by the parasutural reticulate bands (Fig.2A,C,F,H) and the archeopyle. Paratabulation formula interpreted as ?pr, 4", 6"", Xc, 5""", and 1"""". Small subcircular area at the apex (Fig.2A,F) tentatively interpreted as a preapical paraplate. Paracingulum defined by a reticulate, equatorial ridge. Parasulcus rarely identified.
Variability: The development of reticulation is the major variable within and between populations of C. delicata. The holotype (Fig.2A-C) represents most extreme pandasutural restriction of the reticulation (but best exhibits the salient features of the species), one paratype (Fig.2G,H) exhibits average development of the reticulation, while another (Fig.2D,E) is representative of specimens, in which the reticulation entirely covers most paraplate surfaces.
Dimensions:
Fifty specimens measured: 53(79)105 µm in diameter.
Affinities:
Cassiculosphaeridia delicata is similar to C. reticulata Davey 1969 but is distinguished in being larger (approximately twice as large) and in lacking membranous crests arising from the muri. Although C. delicata is similar in size to C. magna Davey 1974, it has a thinner, more delicate reticulation.