MILIOLIDAE - Acta Palaeontologica Polonica

MILIOLIDAE FROM MIOCENE OF POLAND
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X Quinqueloculina haidingeri d'Orbigny, 1846
(PI. III, Figs 3a-c, 4a-c; Text-figs 16, 17)
1846. Quinqueloculina haidingeri d'Orbigny; A. d'Orblgny, p. 289, PI. 18, Figs 13-15.
1952. Sigmoilina haidingeri (d'Orbigny); A. K. Bogdanowich, p. 162, PI. 24, Fig 1 (non
PI. 25, Fig. 1).
1962. Massilina sp. 2; J. Indans, p. 38, PI. 2, Figs 4,5.
1968. Massilina haidingeri (d'Orbigny); 1. Korecz-Laky, p. 151, PI. 12, Figs 13, 14.
1968. Quinqueloculina haidingeri d'Orbigny; J. P. Margerel, p. 41, PI. 4, Figs 9-11.
1971. Sigmoilina haidingeri haidingeri (d'Orbigny); B. Strashimirov, p. 133, PI. 1,
Fig. 21.
Material. - 5 QS and 15 MS (ColI. No. F-I07, Sec. No. 124, 250-253,
255, 257-260, 312-314, 316, 322-326, 328, 342-345, 348).
Dimensions: QS - L 0.95-1.40; B 0.75-0.95; T 0.5-0.6; MS - L
2.0-2.8; B 2.2-2.8; T 0.6-0.7.
Description. - QS broadly oval, thick, subtriangular in cross-section,
periphery acute; chambers broad, slightly inflated, middle chamber oval,
tapering at both ends and with prominent edge, is nearly the same width
as the last chambers, fifth chamber hardly visible or invisible; MS large,
circular, flat, periphery acute; chambers broad, slightly inflated, smooth,
with regular foldings on the inner edges of chambers in some specimens,
2-3 small and slightly inflated middle chambers are seen in the centre
of the test; wall thick; surface smooth and polished; aperture large, oval,
with sinuate edge and thickened rim.
Variability. Morphological features are constant. Some variation is seen
in the convexity of chambers, which in the juvenile stage may be less
inflated than in adult specimens.
Dimorphism. Massiline forms represent the micro and mega II generations,
quinqueloculine forms are the mega I and mega II generations
(Text-fig. 16). PD: micro - 20Il, mega 1-80Il, mega II - 200-220p.
Remarks. - Massiline forms closely resemble Quinqueloculina buchiana
d'Orbigny MS, the shape of which is identical, but the periphery more
acute; the differences are visible only in sections, which show slightly
inflated chamber walls in the juvenile stage of Q. haidingeri, whereas the
walls of Q. buchiana are flat or concave and the edges are keeled (Textfig.
12). Quinqueloculine forms are easy to distinguish thanks to the
different convexity of chambers, as in the juvenile stage of massiline
forms.
The species is rare in the materials from Wieliczka, and this is why
a more detailed investigation of the internal structure has been carryied
out on the topotypical material from Baden (Text-fig. 17). A large proloculus
of mega II generation is visible in the cross-sections of massiline
and quinqueloculine forms and only two specimens are microspheric.
Juvenile forms of the mega II generation are 3 or 4-chambered when seen
from outside (Text-fig. 17/6, 10).
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