Austrotrillina brunni Marie, 1955

Gedik, Fatma, 2017, First record of the new Neoplanorbulinid species (Foraminifera) from the Early Oligocene in Turkey, Malatya Basin, Eastern Taurids, Geodiversitas 39 (2), pp. 273-284 : 282

Austrotrillina brunni Marie, 1955

( Fig. 6 J-M)

Austrotrillina brunni Marie, 1955: 203 , pl. 9, figs 4-8. — Adams 1968: 85, pl. 6, figs 6, 8. — Sirel 2003: 294, pl. 10, figs 10-16.

DESCRIPTION

Megalospheric form

The test is small and the peripheral margin is rounded in transverse sections ( Fig. 6L). The length of the test ranges from 0.62 to 0.75 mm and the width from 0.39 to 0.49 mm. The spheric megalosphere (0.11 to 0.19 mm in diameter) is followed by small undivided chambers arranged in triloculine mode. Later adult chambers with fine subepidermal partitions are also lined up in triloculine pattern. Two types of subepidermal partitions form small alveolar compartments.

Microspheric form

The small test is triangular with rounded margin in transverse sections. The length of this species is unknown, the width of the test is 0.8 mm. Very small, spherical microsphere is followed by the early chambers arranged in quinqueloculine mode, later chambers arranged in triloculine pattern.