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Aptea notialis
From Fensome et al., 2019:
Aptea notialis, Quattrocchio and Sarjeant, 1992, p.83 (al. 2–235), pl.5, figs.1–4; pl.7, figs.7–8.
Holotype: Quattrocchio and Sarjeant, 1992, pl.5, fig.1; Fensome et al., 2019a, fig.19F.
NOW Pseudoceratium.
Originally Aptea, subsequently (and now) Pseudoceratium.
Age: middle–late Tithonian.
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Original description: [Quattrocchio and Sarjeant, 1992, p.83]:
Aptea notialis sp. nov.
(Plate 5, Figs. 1-4; Plate 7, Figs. 7-8)
Derivatio nominis. L. notialis; southern.
Diagnosis: Membranate, dorso-ventrally compressed cyst having a ceratioid outline involving three horns; apical, antapical and a reduced right lateral horn. A lesser outbulge of the phragma occurs between the antapical and right postcingular horns. Cyst always asymmetrical, the axis connecting the apical and antapical horn being always displaced to the left. Apteate ornament, penitabular; sutures marked by a relative broad pandasutural zone, particularly distinct on the epitract but less conspicuous on the hypotract. The ornament elements generally vary in height between 2 and 5 µm, but they are taller on the apical and antapical horns (9-20 µm). These elements are bifurcate, typically coalescing distally to support a delicate ectophragm. The pattern of the ornamentation forms an incomplete and irregular network, especially conspicuous on the three horns; the ornament is best developed around the cyst's periphery. Paratabulation: 4’, 6'', Xc, 6''', 1''''. Sulcus depressed, lacking ornamentation; ornament also absent from the cingulum. Archaeopyle apical, type (tA); operculum usually free; suture zig-zag, mirroring the pattern of the marginal paraplates.
Figured specimens. Holotype: 2966/2: 15,5/106,5 (Plate 5, Fig. 1); paratype: 2966/2: 18,7/101 (Plate 5, Fig. 2); others: 2966/2: 14,5/100,9: 2966/2: 16/104,9; SEM in horizon 2966 (Plate 7, Figs. 7-8).
Lodgement. Palynological Laboratory, Universidad Nacional del Sur, Bahia Blanca.
Dimensions. Holotype: overall length 75 µm, maximum breadth 55 µm, length of apical horn 20 µm, length of antapical horn 10 mm [sic], length of postcingular horn 9 µm. Paratype: overall length (without operculum) 74 µm, maximum breadth 55 µm, length of antapical horn 15 µm, length of postcingular horn 9 µm. Range: overall lengh (including operculum) 55-73 µm, maximum breadth 50-60 µm, length of apical horn 17-29 µm, length of antapical horn 10-15 µm, length of postcingular horn 5-9 µm (16 specimens measured).
Horizon. 2966 level.
Locality. Puente del Arroyo Picún Leufú.
Remarks. The type species of the genus Aptea. A. polymporha. Is notoriously highly variable in morphology (see Dörhöfer and Davies, 1980, p. 33-36). However, the two polar horns are consistently quite short whereas, in these forms from the Neuquén Basin, they are markedly longer. It should be noted also that the stratigraphical range of A. polymorpha is exclusively within the Lower Cretaceous (Barremian-Aptian): the Argentinian forms are considerably older and may well represent evolutionary intermediates between Pseudoceratium eihiense Helby & May in Helby, 1987 and A. polymorpha.
Aptea notialis, Quattrocchio and Sarjeant, 1992, p.83 (al. 2–235), pl.5, figs.1–4; pl.7, figs.7–8.
Holotype: Quattrocchio and Sarjeant, 1992, pl.5, fig.1; Fensome et al., 2019a, fig.19F.
NOW Pseudoceratium.
Originally Aptea, subsequently (and now) Pseudoceratium.
Age: middle–late Tithonian.
---------------------------------------------------------------------------------------------------
Original description: [Quattrocchio and Sarjeant, 1992, p.83]:
Aptea notialis sp. nov.
(Plate 5, Figs. 1-4; Plate 7, Figs. 7-8)
Derivatio nominis. L. notialis; southern.
Diagnosis: Membranate, dorso-ventrally compressed cyst having a ceratioid outline involving three horns; apical, antapical and a reduced right lateral horn. A lesser outbulge of the phragma occurs between the antapical and right postcingular horns. Cyst always asymmetrical, the axis connecting the apical and antapical horn being always displaced to the left. Apteate ornament, penitabular; sutures marked by a relative broad pandasutural zone, particularly distinct on the epitract but less conspicuous on the hypotract. The ornament elements generally vary in height between 2 and 5 µm, but they are taller on the apical and antapical horns (9-20 µm). These elements are bifurcate, typically coalescing distally to support a delicate ectophragm. The pattern of the ornamentation forms an incomplete and irregular network, especially conspicuous on the three horns; the ornament is best developed around the cyst's periphery. Paratabulation: 4’, 6'', Xc, 6''', 1''''. Sulcus depressed, lacking ornamentation; ornament also absent from the cingulum. Archaeopyle apical, type (tA); operculum usually free; suture zig-zag, mirroring the pattern of the marginal paraplates.
Figured specimens. Holotype: 2966/2: 15,5/106,5 (Plate 5, Fig. 1); paratype: 2966/2: 18,7/101 (Plate 5, Fig. 2); others: 2966/2: 14,5/100,9: 2966/2: 16/104,9; SEM in horizon 2966 (Plate 7, Figs. 7-8).
Lodgement. Palynological Laboratory, Universidad Nacional del Sur, Bahia Blanca.
Dimensions. Holotype: overall length 75 µm, maximum breadth 55 µm, length of apical horn 20 µm, length of antapical horn 10 mm [sic], length of postcingular horn 9 µm. Paratype: overall length (without operculum) 74 µm, maximum breadth 55 µm, length of antapical horn 15 µm, length of postcingular horn 9 µm. Range: overall lengh (including operculum) 55-73 µm, maximum breadth 50-60 µm, length of apical horn 17-29 µm, length of antapical horn 10-15 µm, length of postcingular horn 5-9 µm (16 specimens measured).
Horizon. 2966 level.
Locality. Puente del Arroyo Picún Leufú.
Remarks. The type species of the genus Aptea. A. polymporha. Is notoriously highly variable in morphology (see Dörhöfer and Davies, 1980, p. 33-36). However, the two polar horns are consistently quite short whereas, in these forms from the Neuquén Basin, they are markedly longer. It should be noted also that the stratigraphical range of A. polymorpha is exclusively within the Lower Cretaceous (Barremian-Aptian): the Argentinian forms are considerably older and may well represent evolutionary intermediates between Pseudoceratium eihiense Helby & May in Helby, 1987 and A. polymorpha.