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Samlandia carnarvonensis
From Fensome et al., 2019:
Samlandia carnarvonensis McMinn, 1988, p.150, figs.7A–C. Holotype: McMinn, 1988, figs.7A–C; Fensome et al., 1996, figs.1–3 — p.2081. Age: late Campanian–early Maastrichtian.
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Original description (McMinn, 1988)
Description. Proximate, subspherical to ellipsoidal cyst. The wall is composed of three layers; an endophragm, a periphragm and an ectophragm. The endophragm is 2-3 µm thick and smooth to finely granulate. The periphragm is 0.5 µm thick and developed into a reticulum with cell widths up to 8 µm and
a height up to 2 µm. Lumina are ovaI to polygonal. The endophragm and periphragm are closely appressed while the ectophragm is supported by the walls of the reticulum. A short apical horn, formed by an extension of the periphragm and ectophragm, is usually present. The archeopyle is precingular, type P (3" only), and the operculum is normally free. There is no indication of a parasulcus or a paracingulum.
Size. Pericyst (excluding reticulum); length 64(61)54 µm, width 61(54)50 µm. Twenty specimens were measured.
Comparison. Samlandia carnarvonensis resembles the Late Eocene species Samlandia reticulifera Cookson & Eisenack 1965. It is distinguished by its lower, finer reticulum and the absence of distinctly higher ornament around the equator and at the antapex. The presence of a reticulum aIso distinguishes Samlandia carnarvonensis from the other Late Cretaceous species Samlandia mayi sp. nov. and Samlandia vermicutaria sp. nov. S. carnarvonensis is similar to Deflandrea extrema Cookson & Eisenack 1974, but the description and illustration of the type of the latter do not allow a closer comparison. The type locality of Deflandrea extrema, however, is from a Turonian sequence in Balcatta-1 bore, whereas Samlandia carnarvonensis has a late Campanian to early Maastrichtian range. The two species, therefore, apparently
have distinct and separate stratigraphic ranges.
Type material. Holotype, Fig. 7A-C; F47024, Wapet Rough Range South-l, 711.0-712.0 m, Carnarvon Basin.
Occurrence. Rare to common in the Samlandia carnarvonensis Zone to the Cladopyxidium foveolatum Subzone (late Campanian to early Maastrichtian) of the Carnarvon, Canning, Browse and Bonaparte Basins.
Samlandia carnarvonensis McMinn, 1988, p.150, figs.7A–C. Holotype: McMinn, 1988, figs.7A–C; Fensome et al., 1996, figs.1–3 — p.2081. Age: late Campanian–early Maastrichtian.
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Original description (McMinn, 1988)
Description. Proximate, subspherical to ellipsoidal cyst. The wall is composed of three layers; an endophragm, a periphragm and an ectophragm. The endophragm is 2-3 µm thick and smooth to finely granulate. The periphragm is 0.5 µm thick and developed into a reticulum with cell widths up to 8 µm and
a height up to 2 µm. Lumina are ovaI to polygonal. The endophragm and periphragm are closely appressed while the ectophragm is supported by the walls of the reticulum. A short apical horn, formed by an extension of the periphragm and ectophragm, is usually present. The archeopyle is precingular, type P (3" only), and the operculum is normally free. There is no indication of a parasulcus or a paracingulum.
Size. Pericyst (excluding reticulum); length 64(61)54 µm, width 61(54)50 µm. Twenty specimens were measured.
Comparison. Samlandia carnarvonensis resembles the Late Eocene species Samlandia reticulifera Cookson & Eisenack 1965. It is distinguished by its lower, finer reticulum and the absence of distinctly higher ornament around the equator and at the antapex. The presence of a reticulum aIso distinguishes Samlandia carnarvonensis from the other Late Cretaceous species Samlandia mayi sp. nov. and Samlandia vermicutaria sp. nov. S. carnarvonensis is similar to Deflandrea extrema Cookson & Eisenack 1974, but the description and illustration of the type of the latter do not allow a closer comparison. The type locality of Deflandrea extrema, however, is from a Turonian sequence in Balcatta-1 bore, whereas Samlandia carnarvonensis has a late Campanian to early Maastrichtian range. The two species, therefore, apparently
have distinct and separate stratigraphic ranges.
Type material. Holotype, Fig. 7A-C; F47024, Wapet Rough Range South-l, 711.0-712.0 m, Carnarvon Basin.
Occurrence. Rare to common in the Samlandia carnarvonensis Zone to the Cladopyxidium foveolatum Subzone (late Campanian to early Maastrichtian) of the Carnarvon, Canning, Browse and Bonaparte Basins.