Tetrarchiplagia tithoniana, 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 : 18

Tetrarchiplagia tithoniana n. sp. ( Figs 9J ; 10 )

HOLOTYPE. — MNHN, bât. de Géologie, No. Gg 2001/2089 ( Fig. 10 ).

ETYMOLOGY. — From its occurrence in the Tithonian. MATERIAL EXAMINED. — Two specimens from the type horizon (sample Mue 22).

DIMENSIONS (IN µM). — Length of D and L 190-200, of spinules 90-100, of V 40.

DESCRIPTION

Spicule with a thin, relatively short ventral spine and with A, D and L massive, arranged according to the diagonals of a tetrahedron. Apical spine broken off in both specimens available but, by comparison with other species having D and L with the same type of branching, it might be straight and have a verticil of three spinules. Median bar very short. Spines D and L equal, slightly curved downward, gently tapered distally, and provided with two long spinules in a Vshaped position. Secondary lateral spines missing.

REMARKS

Although the species is only represented by two incomplete specimens, it is well distinguished from the other Mesozoic species of Tetrarchiplagia so far described ( Dumitrica 1982a).

Family SETHOPERIDAE Haeckel, 1881 ,

Figures

FIG. 9. — A-I, Tetrarchiplagia ramosa n. sp.; A, holotype, right lateral view; B-I, paratypes; B, C, left lateral and apical views of the same specimen; D, E, left lateral view and detail of apical spine of the same specimen; F, right lateral view of a specimen showing a smaller angle between D and L; G, oblique ventral view; H, dorsal view of a small specimen with strongly curved D and L; I, left lateral view, detail of the central part showing the slender ventral spine and Ll broken off; J, Tetrarchiplagia tithoniana n. sp., paratype, apical view. Abbreviations: D, dorsal spine; L, primary lateral spine; Ll, left primary lateral spine. Scale bars: A-D, F-H, J, 100 µm; E, I, 30 µm.

FIG. 10. — Tetrarchiplagia tithoniana n. sp., holotype, left lateral view; note that spines A and Lr are broken off. Abbreviations: A, apical spine; D, dorsal spine; Ll, left primary lateral spine; Lr, right primary lateral spine; V, ventral spine. Scale bar: 0.1 mm.