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Ambonosphaera hemicavata
Ambonosphaera hemicavata, Prauss, 1989
Holotype: Prauss, 1989, pl.10, figs.8,12; text-fig.9
Locus typicus: Near Hildesheim, NW-Germany
Stratum typicum: Late Bajocian-Early Callovian
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Original description: [Prauss, 1989, p.31-32]: (Translation: LPP):
Description:
Shape of cyst subovoidal to ellipsoidal. Wall composed of pedium and luxuria. Pedium solid, luxuria fossulate, alveolate, rugulate to baculate. On hypocyst baculate structures may expand to longer collumellae, which are longest in the antapical area. Baculae and collumellae connected distally, or are in contact with the tectum, which leads to the development of the typical pericoel. The pericoel surrounds, with exception of the sulcal region, the whole hypocyst. The antapical end of the sulcus is marked by the disconnection of the luxuria. Opistophyle-like openings in the tectum, which vary in number and size, are developed in this region.
Areation: XPR, X", 6"", ?6c, 6""", 1p, 1"""", NRs, FM.
Archaeopyle: apical, operculum secate, archaeopyle outline indicates opercular areation 1"+2"+3"+4". No specimen with operculum in situ was found. Areation is indicated by finate folds and low ridges on the periblast. Plates 1""" and 6""" are very small, 6""" sometimes missing. Larger luxuriate ornaments in finate or peniareate position indicate areation on endoblast.
Dimensions:
(range without operculum): Length 68.4 µm, breadth 60.9 µm, higth of hypopericoel 11.9 µm.
Holotype: Prauss, 1989, pl.10, figs.8,12; text-fig.9
Locus typicus: Near Hildesheim, NW-Germany
Stratum typicum: Late Bajocian-Early Callovian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Prauss, 1989, p.31-32]: (Translation: LPP):
Description:
Shape of cyst subovoidal to ellipsoidal. Wall composed of pedium and luxuria. Pedium solid, luxuria fossulate, alveolate, rugulate to baculate. On hypocyst baculate structures may expand to longer collumellae, which are longest in the antapical area. Baculae and collumellae connected distally, or are in contact with the tectum, which leads to the development of the typical pericoel. The pericoel surrounds, with exception of the sulcal region, the whole hypocyst. The antapical end of the sulcus is marked by the disconnection of the luxuria. Opistophyle-like openings in the tectum, which vary in number and size, are developed in this region.
Areation: XPR, X", 6"", ?6c, 6""", 1p, 1"""", NRs, FM.
Archaeopyle: apical, operculum secate, archaeopyle outline indicates opercular areation 1"+2"+3"+4". No specimen with operculum in situ was found. Areation is indicated by finate folds and low ridges on the periblast. Plates 1""" and 6""" are very small, 6""" sometimes missing. Larger luxuriate ornaments in finate or peniareate position indicate areation on endoblast.
Dimensions:
(range without operculum): Length 68.4 µm, breadth 60.9 µm, higth of hypopericoel 11.9 µm.