Diagnoza

Immediately above S. belkai  in the Kowala section yet another unrelated species of Siphonodella appears that seems to be the oldest Polish member of the main branchof  Siphonodella with a transversely ribbed plafform and a tendency to develop several ridges in the sp elements. Samples Ko-40 and Ko-39 taken at8.2m and7 .6 m below the top of the Kowala section contain sp elements of Siphonodella with one or two ridges developing at the posterior lobe of the platform. They run at a large angle to the element axis, ending approximately at the cusp level, either at the platform margin or in the middle of the platform lobe. The Kowala populations are characteristic in having the whole surface of its platform elements well ornamented. The ridges usually terminate at the level of the cusp, but in some specimens the posterior ridge continues further and approaches gently the platform margin. The tuberculation of the anterior lobe is irregular, which makes this population different from those below and above. In specimens from sample Ko-41, taken at 8.6 m, tubercles tend to be arranged in transverse rows, otherwise the element is of similar morphology to those attributed here tentatively to S. quadruplicata. In younger samples, starting from Ko-38, ati .2m, the tubercles are arranged in longitudinal rows and ridges at the posterior part of the plafform are parallel to its margin. This is probably S. sandbergi that replaced Kowala populations of S. cf . quadruplicata without any intermediates.

A single specimen of the same morphology as those from Kowala has been found in Dzikowiec sNnpleDz-24,located below the fust appearance of S. carinthiaca.

Perhaps the form under discussion is conspecific with Siphonodella quadruplicala (Branson & Mehl, 1934) (Branson & Mehl 1934: pI.24: L8-20, the lectotype selected by Klapper (1966: p. 17) and S. sexplicafa (Branson & Mehl, 1934) from the Bushberg Sandstone at Brickeys in St. Genevieve County of Missouri.

Porównanie

Autekologia

Występowanie geograficzne

Zasięg czasowy

Materiały muzealne

Literatura

Dzik, J. 1997. Emergence and succession of Carboniferous conodont and ammonoid communities in the Polish part of the Variscan sea. Acta Palaeontologica Polonica 42, 57-170.