Cornutella tella, 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 : 48

Cornutella tella n. sp. ( Fig. 24 D-H)

HOLOTYPE. — Photo No. 45641; stub Mue 22/16; Musée de Géologie , Lausanne, No. 74402 ( Fig. 24D ).

ETYMOLOGY. — Arbitrary combination of letters.

MATERIAL EXAMINED. — 12 illustrated specimens and many other specimens not illustrated from the type horizon (sample Mue 22).

DIMENSIONS ( IN µM). — Total length 180-235 (av. 210), length of apical horn and cephalis 50-130 (av. 85), of conical part of thorax 50-75 (av. 60), of inflated part 45-90 (av. 70); maximum width of cephalis at collar boundary 15-30 (av. 20), of conical part of thorax 45-65 (av. 60), of distal part 130-180 (av. 150).

DESCRIPTION

Test high conical with a widely inflated distal part. Cephalis very small, imperforate with a straight apical horn and a short ventral spine, both massive, circular in cross section. Collar boundary not marked outside. Thorax slowly increasing in diametre up to the distal part which is widely inflated, convex in outline as if moulding a spherical calotte. Most proximal part of thorax with infilled pores. Main part of thorax net-like with hexagonally framed pores arranged alternately in commonly 12 longitudinal rows. Size of pores gradually increasing distally. Distal part of test usually not completely developed, without rim, irregular, with thinner bars as if individuals died before completion. Only one specimen of about 20 shows a complete, garlandshaped terminal rim. In this specimen, however, the regular hexagonal pore pattern is strongly disturbed in the terminal pores.

REMARKS

Cornutella tella n. sp. differs from all species of Cornutella so far described by its expanded distal part resembling a spherical calotte.

Figures

FIG. 24. — A-C, I, J, Reticulotubulus tintinnabulum n. sp.; A, B, I, J, holotype, left lateral and basal views with details of the proximal part of shell and of the initial spicule, note prolongation of ventral spine along the tube; C, paratype, right lateral view; D-H, Cornutella tella n. sp.; D, holotype; E-H, paratypes; E, basal view; F, apically broken specimen with garland-shaped distal end; G, young specimen; H, specimen with large terminal pores. Scale bars: A-I, 30 µm; J, 10 µm.