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Pareodinia halosa

Pareodinia halosa (Filatoff, 1975, p.91, pl.29, figs.10–12) Prauss, 1989, p.42. Emendation: Prauss, 1989, p.42, as Pareodinia halosa

Originally Kalyptea, subsequently Kalyptea?, thirdly Caddasphaera, fourthly Pterocystidiopsis (Acritarch), fifthly (and now) Pareodinia.

Holotype: Filatoff 1975. Pl. 29, fig. 10
Locus typicus: Perth Basin, Australia
Stratum typicum: Cadda Formation (Jurassic)
Age: Bajocian

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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.

Pareodinia halosa (Filatoff, 1975) Prauss, 1989, emend. Prauss, 1989. This species has a spherical vesicle, normally folded, particularly parallel to the equator. Wall 1 µm thick, smooth to finely granulate. Vesicle enclosed in an irregular cloak of diffuse tissue which becomes impregnated with sedimentary debris. Size 45-95 µm. According to Prauss (1989, p.42), the archeopyle is 1a+2a+3a, operculum solvate and secate.
Size: overall diameter 45-95 µm, vesicle diameter 37-55 µm.
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Original description: Filatoff 1975, p. 91: Kalyptea halosa
Vesicle spherical, normally much folded, particularly parallel to equator. Wall 1 µm thick, smooth to finely granulate. Vesicle enclosed in an irregular cloak of diffuse tissue which becomes impregnated with sedimentary debris.

Dimensions: Total diameter: 45(63)95 µm. Vesicle diameter: 37(44)55 µm.

Remarks: Kalyptea halosa is similar to K. aceras MANUM & COOKSON, 1964, described from the Late Cretaceous of Artic Canada. The latter is a larger species, however, and the inner surface of its veillike tissue is ornamentated by a network composed of fairly regular meshes. In addition, an apical archaeopyle is apparent in most specimens of K. aceras, but not in K. halosa.

Occurrence: POCOCK (1972, p. 101) recorded similar forms from the Canadian Jurassic. Kalyptea halosa is common in some samples from the Cadda Formation.
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Poulsen, 1996, p. 62
Pareodinia halosa (Filatoff 1975) Prauss 1989
Pl. 4, Figs. 6-8
Remarks. Prauss (1989) described an intercalary archeopyle in this species. In the present study, a small apical? horn was found on some specimens. In most specimens, the small horn is difficult to identify. Pareodinia halosa differs from Pareodinia ceratophora subsp. scopaea in having a much smaller horn. The horn of P. halosa is shorter than 3 µm, whereas the horn of P. ceratophora subsp. scopaea is about 5-8 µm. Pareodinia halosa has not been identified without a kalyptra, whereas P. ceratophora is commonly found without a kalyptra.
Recorded occurrences.
Denmark: Parvocysta nasuta Subzone, Mancodinium semitabulatum Zone - Gochteodinia villosa Zone, Rotosphaeropsis thula Subzone.
Poland: Divisum - Scythicus Zones.
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