Napora avirostrum, 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 : 58

Napora avirostrum n. sp. ( Fig. 28 C-E)

HOLOTYPE. — Photo No. 58511; stub Mue 22/21; Musée de Géologie , Lausanne, No. 74412 ( Fig. 28C ). ETYMOLOGY. — From the Latin avis: bird; and rostrum: beak.

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

DIMENSIONS ( IN µM). — Total length 220-295 (av. 250), length of apical horn 40-50 (av. 45), of cephalis 25-45 (av. 30), of thorax 50-90 (av. 60), of velum 25- 50 (av. 35), of feet 75-150 (av. 100), width of cephalis 35-60 (av. 45), of thorax 95-145 (av. 110).

DESCRIPTION

Cephalis globular, practically imperforate with a three-bladed apical horn. Proximal half of horn thick and strongly expanded at the upper part where blades end up with a crown of very small subsidiary spines, two to three for each blade. Distal part of horn conical, pointed, approximately as long as proximal part. Ventral spine well expressed outside, pyramidal, many-bladed. Boundary between cephalis and thorax difficult to establish outside because there is no visible stricture and the thoracic wall covers the lower part of cephalis. Thorax conical to pyramidal with about five transversal rows of wide pores. Pores alternately arranged, polygonally framed. Transversal ridge above the second basal row of pores sometimes very high. Feet broad, strongly divergent and curved, robust, external ridge forming a longitudinal ridge along thorax. Velum short slightly lobate, with very small pores.

REMARKS

This species resembles Napora schaudibergensis n. sp. in general characters but differs by having a much wider thorax and feet much more divergent and much more curved inward. Some specimens have a very strong transversal rib on thorax. The apical horn is also thinner than that of N. schaudibergensis n. sp.

Figures

FIG. 28. — A, B, Napora aranea n. sp.; A, holotype, view from Ll; B, paratype, dorsal view; C-E, Napora avirostrum n. sp.; C, holotype, view from Lr; D, E, paratypes; D, dorsal view; E, view from Lr; F, G, Napora bondoca n. sp.; F, holotype, view from Ll; G, paratype, view from Ll; H, Napora burckhardti Pessagno, Whalen & Yeh, 1986, dorsal view; I-K, Napora cristata n. sp.; I, holotype, right lateral view; J, K, paratypes; J, right lateral view; K, view from Ll; L, M, Napora divaricata n. sp., holotype, ventral and basal views. Abbreviations: Ll, left primary lateral spine; Lr, right primary lateral spine. Scale bars: A-E, H, K, 100 µm; F, G, I, J, L, M, 30 µm.