Aulosina, Rigaud & Martini & Rettori, 2013

Rigaud, Sylvain, Martini, Rossana & Rettori, Roberto, 2013, A new genus of Norian involutinid foraminifers: Its morphological, biostratigraphic, and evolutionary significance, Acta Palaeontologica Polonica 58 (2), pp. 391-405 : 393

Genus Aulosina nov.

Type species: Triasina oberhauseri Koehn−Zaninetti and Brönnimann, 1968 ; Norian Dachstein limestone of the Dolomites ; Grünau, Almtal, Austria .

Species included: The type species and probably also “ Aulotortus ” bulbus Ho in Ho and Hu, 1977.

Etymology: Aulo from Aulotortus and sina from Triasina , the name contraction of the two genera that resemble it the most.

Material.—The description of this genus is based on about

250 sectioned specimens from rock thin sections stored at the MHNG (collection 2011−1).

Association.—Abundant foraminifers (e.g., Involutinidae , Duostominidae , Oberhauserellidae , Polymorphinidae ), gastropods, bivalves (e.g., megalodontids, wallowaconchids), brachiopods, echinoderms, sponges, corals, spongiomorphs, ostracods, common algae (e.g., dasycladaceans, Codiacea), calcimicrobes, rare serpulids, bryozoans, and diverse problematica.

Description.—The test is free, lenticular to globular, possibly biumbilicate. Globular proloculus followed by a sigmoidally to planispirally enrolled undivided tubular chamber that gradually enlarged from whorl to whorl. Inner strengthenings of the tube wall laterally constrict the tubular chamber lumen. Lateral laminar extensions of the tube wall (lamellae sensu Piller 1978) are developed on both sides of the tubular chamber, possibly building umbilical masses. Wall calcareous, perforate, probably originally hyaline, fibrous and aragonitic. Aperture simple, terminal (open end of the tubular chamber).

Remarks.—The new genus differs from Triasina Majzon, 1954 by its lenticular shape, a different internal tube structure (no pillars), a non overlapping (evolute) tubular chamber and a wider umbilical mass.

Stratigraphic and geographic range.—Norian–lower Rhaetian of Tethys and upper Carnian?–Norian of Panthalassa.