Thamnasterites astraeoides, Roniewicz, 2011

Roniewicz, Ewa, 2011, Early Norian (Triassic) corals from the Northern Calcareous Alps, Austria, and the intra-Norian faunal turnover, Acta Palaeontologica Polonica 56 (2), pp. 401-428 : 425-426

Thamnasterites astraeoides sp. nov.

Fig. 6F.

Etymology: From Latin astraea, star.

Holotype: An incomplete colony GBA 2009 /019/4.

Type locality: Austria, Northern Calcareous Alps, southern Dachstein Plateau, north of Feisterscharte.

Type horizon: Norian, Lacian 1, massive, organodetrital limestone at the horizon with the Epigondolella quadrata Conodont Zone.

Diagnosis.—Adult corallites about 4 mm in diameter. Radial elements thick, ca. 20 in number.

Material.—The holotype with thin sections.

Measurements (in mm):

d adults c−c s eh 4 3–5 12–22 (6+6+S3) 0.2–0.25

Description.—Colony lamellate, corallites astraeoid arranged homogeneously, their radial elements nonconfluent. Costosepta fusiform and very thick with the exception of the internal edge. The fusiform morphology shows that the costosepta were exsert, so the neighbouring calices were probably separated by a depression. Septa differentiated into three size orders subequal in thickness: the S1 septa approaching near the center, the S2 septa considerably shorter, the S3 septa very short. Septal surface covered with rare large, flat pennula−like micromorphology. Wall lacking. Dissepiments vesicular. Budding intercalicular.

The traces of the microstructure are preserved as a dark line (dots in linear arrangement?) in the septal mid−line, and as more or less dispersed dots in the remaining parts of septa. The above traces, peculiar for the small−corallite coral, are doi:10.4202/app.2009.0092

uncomparable to microstructural remains in other Triassic corals recognised so far.

Stratigraphic and geographic range.—Like the holotype.