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Valensiella delicata
Valensiella delicata (Stover and Helby, 1987) Lentin and Williams, 1993
Originally Cassiculosphaeridia, subsequently (and now) Valensiella.
Holotype: Stover and Helby, 1987a, figs.2A–C; Stevens, 1987, figs.9K–M; Fensome et al., 1996, figs.1–3 — p.2107.
Locus typicus: Carnarvon Basin, Australia
Stratum typicum: Berriasian
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Valensiella delicata (Stover and Helby, 1987a) Lentin and Williams, 1993. This species is proximate and subspherical. Autophragm smooth, about 1 µm thick, 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. Muri 1.5 µm or less, variable in thickness, 2-6 µm high outlining circular to polygonal lumina 2-8 µm diameter, but usually less than 5 µm.
Size: diameter 53-105 µm.
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Original description: Stover and Helby, 1987, p. 103: Cassiculasphaeridia delicata
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. Fifty specimens measured 53(79)105 µm in diameter.
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.
Affinities:
Stover and Helby, 1987, p. 103: Cassiculasphaeridia delicata
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.
Originally Cassiculosphaeridia, subsequently (and now) Valensiella.
Holotype: Stover and Helby, 1987a, figs.2A–C; Stevens, 1987, figs.9K–M; Fensome et al., 1996, figs.1–3 — p.2107.
Locus typicus: Carnarvon Basin, Australia
Stratum typicum: Berriasian
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Valensiella delicata (Stover and Helby, 1987a) Lentin and Williams, 1993. This species is proximate and subspherical. Autophragm smooth, about 1 µm thick, 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. Muri 1.5 µm or less, variable in thickness, 2-6 µm high outlining circular to polygonal lumina 2-8 µm diameter, but usually less than 5 µm.
Size: diameter 53-105 µm.
--------------------------------------------------
Original description: Stover and Helby, 1987, p. 103: Cassiculasphaeridia delicata
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. Fifty specimens measured 53(79)105 µm in diameter.
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.
Affinities:
Stover and Helby, 1987, p. 103: Cassiculasphaeridia delicata
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.