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Thalassiphora bononiensis
Thalassiphora bononiensis Corradini, 1973
Originally (and now) Thalassiphora, subsequently Disphaeria. Yun, 1981 transferred this species to Disphaeria Cookson and Eisenack, 1960; however, Lentin and Williams, 1985 retained it in Thalassiphora.
Holotype: Corradini, 1973, pl.30, fig.6a-b
Locus typicus: Castel di Casio, Bologna, Italy
Stratum typicum: Late Cretaceous-Paleocene
Original diagnosis: Corradini, 1973, p.185
Dinoflagellate cyst with spherical to ovoidal central body having an irregularly punctate wall surface, which is up to 2 µm in thickness. Periphragm in form of a wide perforated membrane arising from the dorsal side of the ccntral body. Reflected tabulation 1", 1a, 5",--, 4""", 1"""". Archeopyle precingular.
Dimensions--Holotype: diameter of the central body 60x70 µm, overall diameter 120x 140 µm, dimensions of the archeopyle 28-40 µm. Range: diameter of the central body 46(53)64x55(63)74 µm, overall diameter 70(90)125x80(120)170 µm, dimensions of the archaeopyle 22(24)30x28-(32)42 µm.
Original descriplion: Corradini, 1973, p.185-186
The punctate structure of the endophragm gives a porous appearance to the two sides of the wall. The periphragm, on the contrary, is smooth or lightly fibrous, more normally wrinkled. It arises from the central body as sutural crests, proximally united and distally extending in a continuous perforate "Iamellar wing". The fairly thick membrane, up to 1 µm in thickness, extends to the ventral side of the cyst assuming a "helmet-shaped" appearance, circular to rhomboidal in outline. The continuous margins of the membrane are often turned over. Perforations are subcircular in outline and of different widths, being more numerous near the distal margins of the periphragm, where often the full part of the wing is extremely reduced.
Narrow transversal furrow, often marked by proximal rectilinear crests of the periphragm or by parallel rows of short appendages, located below the archeopyle, on the dorsal surface of the cyst. The wide precingular archeopyle is convex-triangular in outline.
Affinities:
Corradini, 1973, p.186: T bononiensis is very close to T. pelagica (Eisenack) from which it differs chiefly in the ornamentation and in the thicket wall as well as in the larger amount of perforations on the outer membrane. These characters, together with the absence of an antapical keel, justify the creation of a new species.
Originally (and now) Thalassiphora, subsequently Disphaeria. Yun, 1981 transferred this species to Disphaeria Cookson and Eisenack, 1960; however, Lentin and Williams, 1985 retained it in Thalassiphora.
Holotype: Corradini, 1973, pl.30, fig.6a-b
Locus typicus: Castel di Casio, Bologna, Italy
Stratum typicum: Late Cretaceous-Paleocene
Original diagnosis: Corradini, 1973, p.185
Dinoflagellate cyst with spherical to ovoidal central body having an irregularly punctate wall surface, which is up to 2 µm in thickness. Periphragm in form of a wide perforated membrane arising from the dorsal side of the ccntral body. Reflected tabulation 1", 1a, 5",--, 4""", 1"""". Archeopyle precingular.
Dimensions--Holotype: diameter of the central body 60x70 µm, overall diameter 120x 140 µm, dimensions of the archeopyle 28-40 µm. Range: diameter of the central body 46(53)64x55(63)74 µm, overall diameter 70(90)125x80(120)170 µm, dimensions of the archaeopyle 22(24)30x28-(32)42 µm.
Original descriplion: Corradini, 1973, p.185-186
The punctate structure of the endophragm gives a porous appearance to the two sides of the wall. The periphragm, on the contrary, is smooth or lightly fibrous, more normally wrinkled. It arises from the central body as sutural crests, proximally united and distally extending in a continuous perforate "Iamellar wing". The fairly thick membrane, up to 1 µm in thickness, extends to the ventral side of the cyst assuming a "helmet-shaped" appearance, circular to rhomboidal in outline. The continuous margins of the membrane are often turned over. Perforations are subcircular in outline and of different widths, being more numerous near the distal margins of the periphragm, where often the full part of the wing is extremely reduced.
Narrow transversal furrow, often marked by proximal rectilinear crests of the periphragm or by parallel rows of short appendages, located below the archeopyle, on the dorsal surface of the cyst. The wide precingular archeopyle is convex-triangular in outline.
Affinities:
Corradini, 1973, p.186: T bononiensis is very close to T. pelagica (Eisenack) from which it differs chiefly in the ornamentation and in the thicket wall as well as in the larger amount of perforations on the outer membrane. These characters, together with the absence of an antapical keel, justify the creation of a new species.