Back
Disphaeria bononiensis

Disphaera bononiensis (Corradini, 1973) Yun, 1981

Now Thalassiphora. Originally (and now) Thalassiphora, subsequently Disphaeria.
Lentin and Williams, 1985, retained this species in Thalassiphora Eisenack and Gocht, 1960.
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: Thalassiphora bononiensis
Dinoflagellate cyst with spherical to ovoidal central body having an irregularly punctate wall surface, which is up to 2 Ám 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 Ám, overall diameter 120x140 Ám, dimensions of the archeopyle 28-40 Ám. Range: diameter of the central body 46(53)64x55(63)74 Ám, overall diameter 70(90)125x80(120)170 Ám, dimensions of the archaeopyle 22(24)30x28-(32)42 Ám.

Original descriplion: Corradini, 1973, p.185-186: Thalassiphora bononiensis
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 1Á in thickness, extcnds 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 difrerent wiclths, being more numerous near the distal margins of the periphragm, where often the full part ol the wing is extremely reduced.
Narrow transversal furrow, often marked by proximal rectilinear crests of the periphragm or by parallel rows of short appendages, locatcd below the archeopyle, on the dorsal surface of the cyst. The wide precingular archeopyle is convex-triangular in outline.

Affinities:
Corradini, 1973, p.186: Thalassiphora bononiensis
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 crection of a new species.
Feedback/Report bug