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Deflandrea fuegiensis
From Fensome et al., 2019:
Deflandrea fuegiensis Menéndez, 1965, p.8–9, pl.1, figs.1–3; pl.3, fig.16. Holotype: Menéndez, 1965, pl.1, fig.1; pl.3, fig.16.
Age: Late Cretaceous.
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Original description: [Menéndez, 1965] (translated from Spanish):
Deflandrea fuegiensis sp. Nov. (Plate I, Figs. 1-3, and Plate III, Fig. 16)
DIAGNOSIS. Broadly fusiform theca with a smooth or fine, irregularly granulated surface, with two appendages or antiapical horns. The epitheca is taller than the hypotheca, with a conical apex and a slight neck, and an approximately polygonal opening on the dorsal surface. Hypotheca with two irregularly conical antiapical horns. Excavated cingulum with a granulated margin, interrupted on the ventral surface by the longitudinal sulcus. The longitudinal sulcus is slightly marked in the epitheca, widening at the cingulum and opening at its distal end toward the antiapical horns. The cyst is rounded with an oblong opening on the dorsal surface of the apical zone, and the membrane is thin and irregularly granulated.
HOLOTYPE. Prep. 1247(1) BA PB, coord. 34.2-89.4, microse. Watson 90.128
DIMENSIONS. Total length (with appendages), 112.5 μ; maximum width, 67.5 μ; cingulum width, 6.5 μ; transverse axis of the cyst, 67.5 μ; longitudinal axis, 54 μ.
DISTRIBUTION. – 1121 to 1812 m depth.
DESCRIPTION. The holotype (Plate I, Fig. 1) has a theca that is generally fusiform, widened, but somewhat angular. Its surface is largely smooth; but in certain parts, generally close to the equator, it has fine, irregular granulation.
The epitheca, higher than the hypotheca, is conical with convex or somewhat angular lateral margins, but with a slight inflection at the apical part like a neck; on its dorsal surface, it has an opening with an approximately widened pentagonal outline, which, due to its position, would correspond to an intercalary archeopyle. No plate delimitation is visible, although certain folds or breaks in the theca seem to suggest traces of apical and precingular plates; but this is very unclear and not confirmed in other specimens.
The hypotheca, evidently lower than the epitheca, is more or less truncated-conical in shape, the lower angles of which extend into two irregularly conical appendages or horns in a subparallel position.
The cingulum, excavated in the equatorial zone, divides the theca into two unequal parts and is clearly visible on both the dorsal and ventral surfaces; it has a constant width of 6.5 μ, the marginal edges of which are regularly granulated or toothed; on the ventral surface, the continuity of the cingulum is interrupted by the longitudinal sulcus.
The sulcus, marked in the epitheca by a slight oblong notch 10 μ high, widens at the cingulum and upper part of the hypotheca, opening abruptly at its distal end towards the antiapical horns.
Inside, the theca has a body (or cyst, for some authors) that occupies the entire width and approximately two-quarters of the height of the theca. Somewhat elongated transversely, it measures 67.5 µ on its transverse axis and 54 µ on the longitudinal axis. On the dorsal side of the apical part, it has an oblong opening that is slightly below the pentagonal opening of the theca. The cyst membrane is approximately 1 µ thick, thickening towards the cingulate area. It is irregularly granular and more noticeable than that of the theca
From the apex to the antiapical appendages, this specimen measures 112.5 μ in length and 67.5 μ in maximum width in the equatorial zone.
Specimen 1301(2), coord. 35.4-84.9 (Plate I, fig. 2), differs somewhat in its general appearance from the holotype specimen, mainly due to the more pointed apex and the reduction of its antiapical appendages, although one of them appears to be broken. The size of the cyst is 78 by 72 μ, and the total height is 130 μ.
Specimen 1301 (2), coord. 34.2-89.4 (Plate 1, Fig. 3), has one of the antiapical appendages reduced. The total height is 130 μ; the maximum width is 67.5 μ, and the cyst size is 67.5 by 66 μ.
COMPARISONS. Deflandrea fuegiensis is very similar to D. phosphoritica Eisenack, especially to those specimens described by Manum (1960) for the Lower Tertiary of Spitsbergen, but the Tierra del Fuego species can be differentiated by the greater development of its epitheca, the thinner cyst membrane, the larger size of the epitheca in relation to the hypotheca, and the more pronounced cingulum in some specimens.
Furthermore, in almost all specimens of D. phosphoritica, the theca separates laterally from the cyst at the hypotheca, and the less developed epitheca partially contours the cyst
Another species of Deflandrea also similar to D. fuegiensis is D. robusta Deflandre and Cookson (1955), from the lower Eocene of Princetown, Australia, although distinguishable from D. fuegiensis by its non-excavated cingulum separating the theca into two more or less equal parts, and by its smooth cyst.
Deflandrea fuegiensis Menéndez, 1965, p.8–9, pl.1, figs.1–3; pl.3, fig.16. Holotype: Menéndez, 1965, pl.1, fig.1; pl.3, fig.16.
Age: Late Cretaceous.
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Original description: [Menéndez, 1965] (translated from Spanish):
Deflandrea fuegiensis sp. Nov. (Plate I, Figs. 1-3, and Plate III, Fig. 16)
DIAGNOSIS. Broadly fusiform theca with a smooth or fine, irregularly granulated surface, with two appendages or antiapical horns. The epitheca is taller than the hypotheca, with a conical apex and a slight neck, and an approximately polygonal opening on the dorsal surface. Hypotheca with two irregularly conical antiapical horns. Excavated cingulum with a granulated margin, interrupted on the ventral surface by the longitudinal sulcus. The longitudinal sulcus is slightly marked in the epitheca, widening at the cingulum and opening at its distal end toward the antiapical horns. The cyst is rounded with an oblong opening on the dorsal surface of the apical zone, and the membrane is thin and irregularly granulated.
HOLOTYPE. Prep. 1247(1) BA PB, coord. 34.2-89.4, microse. Watson 90.128
DIMENSIONS. Total length (with appendages), 112.5 μ; maximum width, 67.5 μ; cingulum width, 6.5 μ; transverse axis of the cyst, 67.5 μ; longitudinal axis, 54 μ.
DISTRIBUTION. – 1121 to 1812 m depth.
DESCRIPTION. The holotype (Plate I, Fig. 1) has a theca that is generally fusiform, widened, but somewhat angular. Its surface is largely smooth; but in certain parts, generally close to the equator, it has fine, irregular granulation.
The epitheca, higher than the hypotheca, is conical with convex or somewhat angular lateral margins, but with a slight inflection at the apical part like a neck; on its dorsal surface, it has an opening with an approximately widened pentagonal outline, which, due to its position, would correspond to an intercalary archeopyle. No plate delimitation is visible, although certain folds or breaks in the theca seem to suggest traces of apical and precingular plates; but this is very unclear and not confirmed in other specimens.
The hypotheca, evidently lower than the epitheca, is more or less truncated-conical in shape, the lower angles of which extend into two irregularly conical appendages or horns in a subparallel position.
The cingulum, excavated in the equatorial zone, divides the theca into two unequal parts and is clearly visible on both the dorsal and ventral surfaces; it has a constant width of 6.5 μ, the marginal edges of which are regularly granulated or toothed; on the ventral surface, the continuity of the cingulum is interrupted by the longitudinal sulcus.
The sulcus, marked in the epitheca by a slight oblong notch 10 μ high, widens at the cingulum and upper part of the hypotheca, opening abruptly at its distal end towards the antiapical horns.
Inside, the theca has a body (or cyst, for some authors) that occupies the entire width and approximately two-quarters of the height of the theca. Somewhat elongated transversely, it measures 67.5 µ on its transverse axis and 54 µ on the longitudinal axis. On the dorsal side of the apical part, it has an oblong opening that is slightly below the pentagonal opening of the theca. The cyst membrane is approximately 1 µ thick, thickening towards the cingulate area. It is irregularly granular and more noticeable than that of the theca
From the apex to the antiapical appendages, this specimen measures 112.5 μ in length and 67.5 μ in maximum width in the equatorial zone.
Specimen 1301(2), coord. 35.4-84.9 (Plate I, fig. 2), differs somewhat in its general appearance from the holotype specimen, mainly due to the more pointed apex and the reduction of its antiapical appendages, although one of them appears to be broken. The size of the cyst is 78 by 72 μ, and the total height is 130 μ.
Specimen 1301 (2), coord. 34.2-89.4 (Plate 1, Fig. 3), has one of the antiapical appendages reduced. The total height is 130 μ; the maximum width is 67.5 μ, and the cyst size is 67.5 by 66 μ.
COMPARISONS. Deflandrea fuegiensis is very similar to D. phosphoritica Eisenack, especially to those specimens described by Manum (1960) for the Lower Tertiary of Spitsbergen, but the Tierra del Fuego species can be differentiated by the greater development of its epitheca, the thinner cyst membrane, the larger size of the epitheca in relation to the hypotheca, and the more pronounced cingulum in some specimens.
Furthermore, in almost all specimens of D. phosphoritica, the theca separates laterally from the cyst at the hypotheca, and the less developed epitheca partially contours the cyst
Another species of Deflandrea also similar to D. fuegiensis is D. robusta Deflandre and Cookson (1955), from the lower Eocene of Princetown, Australia, although distinguishable from D. fuegiensis by its non-excavated cingulum separating the theca into two more or less equal parts, and by its smooth cyst.