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Pareodinia mangaotanensis

Pareodinia mangaotanensis Schiøler and Crampton, 2014, p.224, figs.9A–D.
Holotype: Schiøler and Crampton, 2014, fig.9C.
Age: late Cenomanian.

Original description Schiøler and Crampton, 2014
Derivation of name. After the Mangaotane Stream section where the holotype is from.
Holotype. Sample X16/f271 (MNGT2), Slide L22607/2, EF coordinates V31/0, Fig. 9, C. Horizon. Karekare Formation at 6.8 m on the measured section at Mangaotane Stream ( Fig. 4), lower Arowhanan (upper Cenomanian). Repository of type. The palynological collection of GNS Science, 1 Fairway Drive, Avalon, Lower Hutt. Paratypes. Sample X16/f281 (MNGT12), slide L22617/2, EF coordinates S40/1, Fig. 9, A. Sample X16/f289 (MNGT19), slide L22624/2, EF coordinates Y30/1, Fig. 9, B. Sample X16/f187 (P20), slide L26403/4, EF coordinates C64/1, Fig. 9, D.

Diagnosis:
Elongate, smooth- and thick-walled, process-free pareodiniacean with a tapering apical horn. Archeopyle formed by loss of two anterior intercalary plates. Description. Intermediate-sized elongate to oval undifferentiated autocyst with a prominent, tapering apical horn and two low antapical bulges. The autophragm is smooth and 1–1.5 μm thick. The apical horn tapers from shortly above the anterior archeopyle margin to form an acute solid apex, sometimes with a small nipple distally ( Fig. 9, B). Antapically, the cyst has two low bulges. In some specimens, the bulges are very shallow and only faintly distinguishable. In a population, cyst size, shape and wall thickness varies only little. The archeopyle is intercallary, type 2I, formed by the loss of two separated anterior intercallary plates of roughly the same size (Fig. 9, A, C). Apart from the archeopyle, there is no indication of paratabulation.

Dimensions.
Five specimens measured (μm) Holotype Range
Length 80 65 (75) 83
Width 50 41 (46) 51
Apical horn length 12 11 (12) 12

Stratigraphic range:
Ascodinium serratum Zone to the upper part of Hapsocysta peridictya Zone; Arowhanan (upper Cenomanian), excluding the uppermost part of that stage.

Remarks:
The new species resembles Pareodinia? psilata Jain and Millepied 1975 in being smooth-walled. However, Pareodinia mangaotanensis is elongate to oval whereas P.? psilata is subcircular. Further, the archeopyle type of P.? psilata is unknown, whereas that of Pareodinia mangaotanensis is clearly 2I ( Fig. 9, A–C). The new species resembles the specimen figured by Cookson and Eisenack (1958) as P. aphelia (pl. 12, fig. 3), but differs from the type of that species, figured on pl. 12, fig. 4 in being smooth-walled and lacking a kalyptea. It is therefore possible that Cookson and Eisenack (1958) figured more than one taxon under the name P. aphelia in their pl. 12 and that that shown in fig. 3 is conspecific with P. mangaotanensis. The new species differs from other species of Pareodinia in having a smooth cyst wall. Pareodinia mangaotanensis superficially resembles smooth-walled species of Batiacasphaera, in particular B. subtilis which occurs together with the new species in some of the Arowhanan samples studied herein ( Fig. 12, F, Fig. 6, Fig. 7 and Fig. 8). However, species of Batiacasphaera have a four-plate apical archeopyle as opposed to the two-plate intercallary archeopyle of Pareodinia mangaotanensis.
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