Ceriostella sp.

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 : 418

Ceriostella sp.

Fig. 5A–C .

Material.—Nearly complete colonies GBA 2009/019/20 and 2009/019/22, and fragments of colonies GBA 2009/019/3, 2009/019/5, 2009/019/7 and 2009/019/23, with thin sections. The skeletons are deeply recrystallised.

Material and measurements (in mm) made on thin sections: Description.—Colonies from lamellar to massive, more than 100 mm in height. Corallites densely packed, polygonal. Radial elements differentiated into three size orders, with the S1septa the thickest and approaching the centre, the S2 septa shorter and much thinner than the S1 septa, and the S3 septa very thin and short. The irregular number of the S1 septa from four to eight results in a variable symmetry of the septal apparatus, allowing for a provisional discrimination of the two groups of specimens indicated above. Because of the extremely limited observations it is impossible to establish whether or not this variability has any diagnostic value. Septal distal border very thin; septal sides with sharp granules. Endotheca dissepimental, vesicular.

Remarks.—The Alpine taxon is close to the North American upper Ladinian species, Ceriostella variabilis Roniewicz and Stanley, 1998 , but its state of preservation precludes any detailed examination of structures or comparison with similar taxa.

Stratigraphic and geographic range.— Austria: Northern Calcareous Alps, Dachstein Plateau, north of Feisterscharte, lower Norian, Epigondolella quadrata Conodont Zone.

Figures

Fig. 5. Margarosmiliid corals from vicinity of Feisterscharte, Austria, early Norian, Triassic. A–C. Ceriostella aff. variabilis Roniewicz and Stanley, 1998. A. GBA 2009/019/20; a colony in polished section. B. GBA 2009/019/22; transverse thin sections (B1, B2), note cerioid colony and a lack of columella; longitudinal section (B3) showing mode of growth of corallites at the periphery of lamellar colony. C. GBA 2009/019/23a; calice in longitudinal/oblique section showing rare granules on the septal side and internal border micromorphology (at the middle). D. Magarosmilia nova Turnšek, 1991; GBA 2009/019/4 i; transverse section. E. Margarophyllia cf. capitata (Münster, 1841); GBA 2009/019/2c; transverse section. F. Thamnomargarosmilia aff. prima Melnikova, 1996; GBA 1995/2/1/2f, c; transverse sections showing budding with lamellar linkages between centres (F1), and a typical circular shape of adult corallite (F2) with a new one growing laterally. G, H. Margarosmilia adhios sp. nov. G. GBA 2009/019/18a; a fragment of transverse section (G1) of a corallite with traces of microstructure; longitudinal section (G2) of corallite showing small dissepiments. H. GBA 2009/019/19a, c; transverse section of phaceloid corallum (H1); a section of the corallite at a preliminary stage of sub−symmetric division (H2).