Pachysolenia cylindrica Cuif, 1975

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 : 407

Pachysolenia cylindrica Cuif, 1975

Fig. 2A .

1975 Pachysolenia cylindrica sp. nov.; Cuif 1975b: 174, text−figs. 8, 9, pl. 14: 4, 5.

1986 Pachysolenia cylindrica Cuif, 1975 ; Melnikova 1986: 87, pl. 20: 2, pl. 21: 2.

2007 Pachysolenia cylindrica Cuif, 1975 ; Roniewicz et al. 2007: 588, pl. 3: 1, 2.

Material.— GBA 2007/152/1, a fragment of a dense, phaceloid corallum; isolated corralites in thin sections from the specimens GBA 2009/019/4, 2009/019/3.

Measurements (in mm):

Remarks.—In the corallites from the above three samples, all with lumen filled with blocky calcite, only the longest septa (S1 and S2) may be observed, the others being destroyed. In contrast to the image suggesting a thick−septal skeleton presented in Fig. 2A 3, the S1 and S2 septa were originally very thin, and only secondarily became covered during diagenesis by a film of calcite crystals of small size that partially enhanced their shape. The calices are tube−like, and devoid of septa. In the calices filled with sediment, the internal surface shows sharp tips of the modules producing the pachythecal wall (compare Roniewicz and Stolarski 1999).

Stratigraphic and geographic range.— Austria: Northern Calcareous Alps, Dachstein Plateau, 50 m north of Feisterscharte, lower Norian, Epigondolella quadrata Conodont Zone. Turkey: Taurus Mountains, Alakir Çay Valley, Stikinoceras kerri Ammonoid Zone. Tajikistan: SE Pamirs, Djilgakochusu Valley, Shaimak svite, upper Carnian–lower Norian.

Figures

Fig. 2. Hexanthiniarian corals from vicinity of Feisterscharte, Austria, early Norian, Triassic. A. Pachysolenia cylindrica Cuif, 1975; GBA 2007/152/1. A fragment of phaceloid corallum in upper view (A1); transverse section (A2); a corallite with septa thickened by a cover of fine crystals (A3); a tube−like, distal part of the calice with a thick pachythecal wall (A4); a magnified fragment showing modular structure of the pachythecal wall with internal wall surface longitudinally sculptured with minute ridges at left (A5); a corallite in longitudinal section showing a thick wall and thin, rare tabulae (A6). B. Pachysolenia cf. cylindrica Cuif, 1975; GBA 2007/152/3. Transverse section of the corallite with abundant septa. C, D. Pachydendron microthallos Cuif, 1975. C. GBA 2007/152/2. Corallum in transverse section (C1); corallite with rare tabulae in longitudinal section (C2); and a corallite (C3) with traces of microstructure in the wall with lumen filled by coarse calcite crystals. D. GBA 2009/019/3. Corallite with recrystallised wall, transverse section. E. Indetermined solitary hexanthiniarian coral?; GBA 2009/019/12. Thick−walled pachythecal−like coral in transverse section (E1), and its fragment (E2) showing septa with sharp ornamentation.