Saitoum kapewinteri, Dumitrica & Zügel, 2003

Dumitrica, Paulian & Zügel, Peter, 2003, Lower Tithonian mono- and dicyrtid Nassellaria (Radiolaria) from the Solnhofen area (southern Germany), Geodiversitas 25 (1), pp. 5-72 : 26

Saitoum kapewinteri n. sp. ( Fig. 15D, E, N )

HOLOTYPE. — Photo No. 38490, 38491; stub Hob 32; Musée de Géologie , Lausanne, No. 74384 ( Fig. 15D, N ). ETYMOLOGY. — The species is named for Dr. Klaus- Peter Winter, Geological and Palaeontological Institute, Frankfurt am Main, Germany.

TYPE LOCALITY. — Horstberg, northern quarry, about 1 km NNE of Mühlheim, 2.5 km S of Solnhofen.

TYPE HORIZON. — Sample Hob 32, 40 cm limestone bed, about 1.5 m below limestones with well preserved ammonites.

MATERIAL EXAMINED. — Of the 15 photographed specimens a single specimen comes from the rich material of sample Mue 22, where the species is extremely rare. All the other specimens were found in the samples Mue 9, SB 3, Hob 32, and Hob 52.

DIMENSIONS ( IN µM). — Length of cephalis 67-78 (av. 73), of feet 55-72 (av. 63), of apical horn 40-60 (av. 50), width of cephalis 74-80 (av. 76).

DESCRIPTION

Cephalis globular, robust, thick-walled, generally poreless except for a few very small pores scattered here and there, three pores at the base of the apical horn, one above each foot, and the pores of the ditreme. Ditreme around the ventral and secondary lateral spines, the former with a much more protruding rim than the latter. Surface densely pustulate. Apical horn long, conical, sometimes with thickened base. Feet slightly longer than apical horn, oval or elliptical in cross section, slightly curved and weakly divergent. Their distal ends pointed, usually with a weak keel on the external side. Distal part of cephalis slightly constricted, bearing a very thick, expanded but short lobe between feet. Elements of initial spicule very robust, flattened laterally. Velum very thin and very rarely preserved.

REMARKS

Morphologically Saitoum kapewinteri n. sp. is very close to S. elegans from which it differs in having commonly small lobes between feet, a shorter cephalis, sensibly shorter, thicker, and less divergent feet. Moreover, a ditreme may exist around the secondary lateral spines. Given all these characters, and the fact that our specimens are older than all the specimens of S. elegans so far illustrated, with a single exception ( Baumgartner et al. 1995: pl. 3022, fig. 3) all Berriasian in age, it is possible that this new species represents the ancestor of S. elegans and is transitional between the latter and S. levium or S. corniculum De Wever, 1981 .

Figures

FIG. 15. — A-C, Saitoum differtum n. sp.; A, B, holotype, right lateral and basal views; C, paratype, left lateral view; D, E, N, Saitoum kapewinteri n. sp.; D, N, holotype; D, view from the left primary lateral spine; N, detail, ventral view; E, paratype, ventral view; F-I, L, Saitoum labeosum n. sp.; F, holotype, dorsal view; G-I, L, paratypes; G, ventral view showing the ditreme; H, broken specimen, right lateral view showing the thin apical spine and thick median bar; I, specimen with distally closed velum; L, basal view showing the left secondary lateral spine prolonged outside (anomaly?); J, K, M, Saitoum macilentum n. sp.; J, M, holotype, dorsal and basal views; K, paratype, left lateral view showing a strong arch Al. Abbreviations: A, apical spine; l, secondary lateral spine. Scale bars: 30 µm.