Gorispela fenestrata, Dumitrică, 2024

Dumitrică, Paulian, 2024, New Middle Triassic Bell-Shaped Nassellarian Radiolaria From Alpine And Carpathian Areas, Acta Palaeontologica Romaniae 20 (1), pp. 51-75 : 58

Gorispela fenestrata n. sp.

Fig. 3b

Diagonisis. Shell dicyrtid, campanulate. Cephalis practically imperforate except for a few small pores at the contact of the secondary lateral rays with the shell wall. Apical and ventral rays of the initial spicule forming two very robust horns diverging at about 90°, its bisectrice tilted at an angle of about 15° relative to the shell axis. Horns robust, conical on the proximal half or more and three-bladed and pyramidal on the distal portion. Apical horn tilted in dorsal direction, and apical ray prolonged along the inner side of the apical horn up to the base of the three-bladed portion. Ventral horn with proximal half conical and thick, and distal half three-bladed with pointed end and thin blades. Ventral ray of the initial spicule straight and very long inside shell, prolonged in the centre of the hollow conical half up to the base of the three-bladed portion. Collar boundary at the level of a circumferential row of small circular pores above the first circumferential ridge or, above it, at the level of MB that is marked at the surface by a constriction at the dorsal part of cephalis or a similar constriction at the base of the ventral horn. Thorax truncate-conical, with three circumferential ridges, the first one sometimes less marked. Each interval between two circumferential ridges with a row of very large oval pores forming a fenestrated structure. Distal end of shell with a thin circumferential band-like rings and, below it, a narrow girdle, both originated in the same place.

Studied material. Six specimens in the sample BV 85-70.

Holotype. Fig. 3b , BV 85-70, coll. MGL.110273.

Dimensions (measured on holotype). Length of shell without apical horn, measured on holotype, 90 µm, of cephalis 57 µm, of thorax 34 µm, diameter of cephalis at its base 64 µm, of distal ring of thorax 127 µm, length of apical horn 65 µm, its diameter at base 27 µm, length of ventral horn 60 µm, its diameter at base 34 µm.

Etymology. From the Latin fenestratus, - a, - um – with windows.

Remarks. This species differs from the other species of the genus Gorispela by having a fenestrate thorax with three circumferential ridges and a very narrow distal cylindrical circle.

Stratigraphic range. Lower Ladinian of sample BV 85- 70 from the Livinallongo Formation.

Figures

Fig. 3. a, a1. – Gorispela cornubovis n. sp., holotype in lateral and basal views, respectively, Rc4; b. – Gorispela fenestrata n. sp., holotype in lateral view, BV 85-70; c-e.– Gorispela hungarica n. sp., FÖ 87, e.– holotype. Scale bar of 50 µm is for all figures.