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Kallosphaeridium dolomiticum
Kallosphaeridium dolomiticum Torricelli, 2000, p.261-262, pl.4, figs.9,12.
Holotype: Torricelli, 2000, pl.4, fig.9.
Age: Late Hauterivian.
Original description (Torricelli, 2000):
Kallosphaeridium dolomiticum sp. nov. [16, Plate IV, 9 and 12].
Kallosphaeridium ?helbyi subsp. psilatum (Burger, 1980) Lentin and Williams, 1989 [135, Plate I, 9].
Kiokansium unituberculatum (Tasch, 1964) Stover and Evitt, 1978 (104).
Kleithriasphaeridium corrugatum Davey, 1974 [37, Plate XXI 1 and 6].
Kleithriasphaeridium eoinodes (Eisenack, 1958) Davey, 1974 [55, Plate XXI, 5].
Kleithriasphaeridium fasciatum (Davey and Williams, 1966) Davey, 1974 [41, Plate XXI, 2].
Kleithriasphaeridium cf. K. fasciatum (Davey and Williams, 1966) Davey, 1974 [98, Plate XXII, 1–3].
Holotype: slide PAT 128-ox, England Finder Coordinate K 31/4 [ Plate IV, 9].
Type locality: Cismon borehole, Belluno Province, Veneto, Italy.
Type stratum: Biancone Formation.
Repository: Palynological slide collection, Stratigraphic Department (STIG) of ENI S.p.A., Agip Division, S. Donato Milanese, Italy.
Etymology: Named after the Dolomites, a mountain region in the immediate vicinity of the type locality.
Diagnosis: A species of Kallosphaeridium possessing hollow spines distally expanded and closed.
Description: Cyst subspherical, proximate, with a smooth, thin autophragm which bears numerous nontabular spines. Spines are smooth and hollow, 3–5 μm in length, gently tapering and distally capitate. Their basal diameter is ca. 2 μm. The archeopyle is apical, type tA. The operculum is attached. Accessory splits between precingular paraplates are present and usually long. Other evidences of paratabulation are absent.
Dimensions: Holotype: central body length=38 μm (without operculum); width=50 μm; processes length=3–4 μm. Range: central body length=35–46 μm (without operculum); width=36–52 μm; processes length=3–5 μm. A total of 11 specimens measured.
Comparisons: The new species differs from all other species of Kallosphaeridium by the morphology of spines. In particular, Kallosphaeridium nigeriaense Jan du Chêne et al. 1984 displays slender acuminate spines.
Stratigraphic occurrence: Upper Hauterivian, Lower Cretaceous of the southern Alps.
Remarks: This form differs from K. fasciatum in possessing tubiform processes connected by thin, membranous crests. These crests may be low or high, in the latter case resulting in an entire encircling flange. Some specimens may superficially resemble the dinoflagellate cyst genus Pterodinium Eisenck 1958, although the striate central body and tubiform processes are distinctive of K. cf. fasciatum. Kleithriasphaeridium corrugatum never develops interconnecting crests between processes.
Stratigraphic occurrence: This taxon was abundantly recovered from a narrow interval of the Cismon core straddling the Lower–Upper Barremian boundary, from 59.50 to 60.90 m. Forms similar to K. cf. fasciatum as described here were found in the Upper Hauterivian of SE Spain ( Leereveld, 1995 and Leereveld, 1997).
Holotype: Torricelli, 2000, pl.4, fig.9.
Age: Late Hauterivian.
Original description (Torricelli, 2000):
Kallosphaeridium dolomiticum sp. nov. [16, Plate IV, 9 and 12].
Kallosphaeridium ?helbyi subsp. psilatum (Burger, 1980) Lentin and Williams, 1989 [135, Plate I, 9].
Kiokansium unituberculatum (Tasch, 1964) Stover and Evitt, 1978 (104).
Kleithriasphaeridium corrugatum Davey, 1974 [37, Plate XXI 1 and 6].
Kleithriasphaeridium eoinodes (Eisenack, 1958) Davey, 1974 [55, Plate XXI, 5].
Kleithriasphaeridium fasciatum (Davey and Williams, 1966) Davey, 1974 [41, Plate XXI, 2].
Kleithriasphaeridium cf. K. fasciatum (Davey and Williams, 1966) Davey, 1974 [98, Plate XXII, 1–3].
Holotype: slide PAT 128-ox, England Finder Coordinate K 31/4 [ Plate IV, 9].
Type locality: Cismon borehole, Belluno Province, Veneto, Italy.
Type stratum: Biancone Formation.
Repository: Palynological slide collection, Stratigraphic Department (STIG) of ENI S.p.A., Agip Division, S. Donato Milanese, Italy.
Etymology: Named after the Dolomites, a mountain region in the immediate vicinity of the type locality.
Diagnosis: A species of Kallosphaeridium possessing hollow spines distally expanded and closed.
Description: Cyst subspherical, proximate, with a smooth, thin autophragm which bears numerous nontabular spines. Spines are smooth and hollow, 3–5 μm in length, gently tapering and distally capitate. Their basal diameter is ca. 2 μm. The archeopyle is apical, type tA. The operculum is attached. Accessory splits between precingular paraplates are present and usually long. Other evidences of paratabulation are absent.
Dimensions: Holotype: central body length=38 μm (without operculum); width=50 μm; processes length=3–4 μm. Range: central body length=35–46 μm (without operculum); width=36–52 μm; processes length=3–5 μm. A total of 11 specimens measured.
Comparisons: The new species differs from all other species of Kallosphaeridium by the morphology of spines. In particular, Kallosphaeridium nigeriaense Jan du Chêne et al. 1984 displays slender acuminate spines.
Stratigraphic occurrence: Upper Hauterivian, Lower Cretaceous of the southern Alps.
Remarks: This form differs from K. fasciatum in possessing tubiform processes connected by thin, membranous crests. These crests may be low or high, in the latter case resulting in an entire encircling flange. Some specimens may superficially resemble the dinoflagellate cyst genus Pterodinium Eisenck 1958, although the striate central body and tubiform processes are distinctive of K. cf. fasciatum. Kleithriasphaeridium corrugatum never develops interconnecting crests between processes.
Stratigraphic occurrence: This taxon was abundantly recovered from a narrow interval of the Cismon core straddling the Lower–Upper Barremian boundary, from 59.50 to 60.90 m. Forms similar to K. cf. fasciatum as described here were found in the Upper Hauterivian of SE Spain ( Leereveld, 1995 and Leereveld, 1997).