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Pyxidinopsis elliptica

Pyxidinopsis elliptica Biffi and Manum, 1988

Holotype: Biffi and Manum, pl.14, fig.7
Locus typicus: Ca" Tosi Section, Schlier Fm.; Central Italy
Stratum typicum: Early Miocene.
Age: Oligocene-early Miocene

Original diagnosis: Biffi and Manum 1988, p. 210
Cyst proximate, ovoidal in shape; autophragm rather thick and rigid; surface covered by low, sinuous crests, producing an irregular reticuloid pattern (Pl. 14, fig. 7). Paratabulation only indicated by precingular archeopyle, type P (3" only), operculum free.

Dimensions: Holotype: cyst length 47.5 µm, cyst breadth 35 µm. Mean values (bracketed) and extremes (n = 10): cyst length 39(47)55 µm; cyst breadth 28(35)38 µm.

Description: Biffi and Manum 1988, p. 210
Cyst proximate, with an ovoidal outline. The wall appears two layered, about 2-3 µm thick; the outer surface is coarsely ornamented with low, sinuous crests, generating an irregular reticuloid pattern, with meshes of variable size and shape, subpolygonal. Sometimes, at optical analysis the crests give an apparent imbricated pattern. The paratabulation is indicated only by the precingular archeopyle, type P (3" only). The operculum is free

Remarks: Biffi and Manum 1988, p. 210
Pyxidinopsis elliptica n. sp. is smaller than P. challengerensis Habib, 1975, is definitely ovoidal, has sinuous rather than straight crests and a relatively smaller archeopyle. Pyxidinopsis elliphca n. sp. differs from Pyxidiella (?) simplex Harland, 1978 (probably a Cerebrocysta) in having a reticulate surface and lacking a prominent dorso-antapical bulge and a protruding paracingular area (cf. Edwards, 1984; Pl. 5, figs. lOA, B = Tectatodinium simplex). This species has been referred to Pyxidinopsis Habib rather than Cerebrocysta Bujak, because of the reticulate surface and the archeopyle, type P (3" only).

Occurrences:
Ca" Tosi PAL 212 - PAL 216 frequent
Monte Conero SR 985 - SR 987 rare to frequent
Montebello d"Urbino PAL 122 - PAL 130 frequent
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