Cheiloceras lagoviense (Gürich, 1901) from the C. quadrantinodosa Zone at Łagów-Dule and Jabłonna in the Holy Cross Mountains.

Diagnoza

Suture with acutely pointed, relatively deep flank lobe and trapezoidal ventrolateral saddle; medium-size discoidal conch with numerous internal thickenings following the course of aperture.

Porównanie

Among  specimens only the lectotype represents this species. The paratype  with radially arranged internal thickenings best visible on flanks and a more globose conch represents another cheiloceratid, possibly Ch. amblylobum. Sobolew’s (1914) Ch. sublagoviense and Ch. longilobum, probably from the same stratum, may be conspecific. The latter species probably corresponds to more globose variants deviating from the main trajectory of the Ch. lagoviense ontogeny. This deviation is strong enough to suspect that a separate species is represented in the sample. Unquestionably homogenous natural assemblage is necessary to prove this.

Autekologia

Występowanie geograficzne

Łagów-Dule, possibly also at Jabłonna.

Zasięg czasowy

C. quadrantinodosa and C. marginifera Zones.

Materiały muzealne

ZPAL: 37 specimens.

Literatura

Dzik, J. 2006. The Famennian "Golden Age" of conodonts and ammonoids in the Polish part of the Variscan sea. Palaeontologia Polonica 63, 1-359.