Cassideus deweveri, 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 : 42

Cassideus deweveri n. sp. ( Figs 21E, F ; 22 )

HOLOTYPE. — Photo No. 58119; stub Mue 22/20; Musée de Géologie , Lausanne, No. 74397 ( Fig. 21E ) . PARATYPES. — MNHN, bât. de Géologie, No. Gg 2001/2100-2101.

ETYMOLOGY. — The species is named for Prof. Patrick De Wever (MNHN) to honour his valuable contribution to the knowledge of Mesozoic and Paleozoic radiolarians.

MATERIAL EXAMINED. — Four specimens from the type horizon (sample Mue 22).

DIMENSIONS ( IN µM). — Height of test without horns 118-125, of proximal part 47-50, of middle and distal part of thorax 55-65, of skirt 20-30, diametre of thorax at the boundary between proximal and middle part 65-75, at the boundary with skirt 90-92, maximum diametre of skirt 118-130, length of apical and ventral horns 60-65.

DESCRIPTION

Test high, conical, with apical and ventral horns robust. Apical horn curved, obliquely upward directed, ventral horn straight or very weakly curved, inclined about 30° above the horizontal plane. Both bladed proximally and massive medially and distally. Cephalis with small pores, externally undistinguished from the proximal part of thorax with which it forms a low cone. Middle and distal part of thorax high conical to subcylindrical, straight or weakly constricted medially, well separated from the proximal part and thoracic skirt by the change in outline, and having nine to 10 transverse rows of alternate pores. Thoracic skirt expanded at an angle of about 50° below the horizontal plane and bearing four to six transverse rows of alternate pores.

REMARKS

Cassideus deweveri n. sp. resembles C. biannulatus n. sp. by having a rather similar shape and two robust horns but differs from it by being slightly higher, by the lack of two circumferential thoracic ridges, and by the less expanded thoracic skirt.

Figures

FIG. 21. — A-D, L, Cassideus biannulatus n. sp.; A, B, holotype, left lateral and basal views; C, D, L, paratypes; C, right lateral view; D, latero-apical view; L, basal view of initial spicule showing the absence of dorsal spine; E, F, Cassideus deweveri n. sp.; E, holotype, left lateral view; F, paratype, right lateral view; G-I, Cassideus scalariconus n. sp.; G, H, holotype, right lateral and basal views; I, paratype, left lateral view; J, K, Cuniculiformis sp., fragment, basal and left lateral views. Scale bars: A-K, 30 µm; L, 10 µm.

FIG. 22. — Cassideus deweveri n. sp., paratypes MNHN, bât. de Géologie, No. Gg 2001/2100 and MNHN Gg 2001/2101, in left lateral and right lateral views respectively, shape of shell and place of the initial spicule. Abbreviations: A, apical horn; L, primary lateral spine; l, secondary lateral spine; V, ventral spine. Scale bar: 0.1 mm.