Acuticassis gotica, 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 : 38

Acuticassis gotica n. sp. ( Fig. 20 )

HOLOTYPE. — Photo No. 58426-58428; stub Mue 22/21; Musée de Géologie, Lausanne, No. 74395 ( Fig. 20A, B, H ).

ETYMOLOGY. — From the Latin goticus: Gothic, for the Gothic outline of the test.

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

DIMENSIONS ( IN µM). — Total length 230-300 (av. 265), length of cephalis 135-175 (av. 160), of apical horn 60-80 (av. 70), of feet 35-110 (av. 60), width of cephalis 140-165 (av. 150).

DESCRIPTION

Cephalis rounded conical with the wall supported by the primary arches forming well marked ridges interconnected by secondary ridges of various directions and lengthes. Pores polygonal, commonly triangular and quadrangular, resulting from connecting bars between ridges. Initial spicule thin, with a long median bar. Apical horn long, straight, with three wide blades at its base directed and connected to the arches AV and Al. Blades perforated by polygonal pores similar to those of the cephalic wall. Feet straight, threebladed, aligned to D and L, and diverging at an angle of about 45° to the axis of shell. V and l marked outside by very short vertices. Base of cephalis with a broad, slightly expanded rim connected to the blades of the feet. Inner part of rim slightly constricted, with remains of a probably thin and short postcephalic velum.

REMARKS

See under the genus.

Superfamily FOREMANELLINACEA Dumitrica, 1982

Family CUNICULIFORMIIDAE De Wever, 1982 TYPE GENUS. — Cuniculiformis De Wever, 1982 .

RANGE. — Middle Triassic (lower Ladinian) to Upper Cretaceous (Cenomanian).

EMENDED DIAGNOSIS. — Dicyrtid nassellarians whose initial spicule has no dorsal spine and whose apical and ventral spines are usually extended outside test wall into long horns. Cephalis small. Thorax much larger than cephalis, bell-shaped, conical or cylindrical, simple or with one or more external circumferential ridges, with or without thoracic skirt (Dumitrica in De Wever et al. 2001).

REMARKS

Originally the family was described as comprising monocyrtid nassellarians with cephalic wall prolonged into a velum. This velum is, however, a true thorax similar to the thorax of the family Neosciadiocapsidae Pessagno, 1969 . The family should therefore be considered as comprising dicyrtid rather than monocyrtid nassellarians. Until present the family was reduced to the genus Cuniculiformis De Wever, 1982 . In this paper we also include the genus Cassideus Pessagno, 1969 in this family for the reasons presented below.

Figures

FIG. 20. — Acuticassis gotica n. gen., n. sp.; A, B, H, holotype, right lateral and basal views showing details of initial spicule respectively; C-G, I, paratypes; C, D, I, partly broken specimen, dorsal and basal views showing details of the initial spicule in dorsal view respectively; E, left lateral view; F, G, dorsal and basal views of same specimen. Scale bars: A-G, 30 µm; H, I, 10 µm.