Periodon aculeatus Hadding, 1913 late form from the Mjcya Limestone.

Diagnoza

External processes in the symmetry transition series and the ne elements reduced, with very small denticles.

Porównanie

The species is extremely rare in Mójcza and little can be added to the reconstruction of its apparatus in DZIK (1976). In the course of the evolution of the Periodon lineage non-inner processes in the elements of the symmetry transition series gradually disappeared (see DZIK 1976, 1983; STOUGE and BAGNOLI 1988). This can be recognized also within the chronospecies P. aculeatus, in its present mening. Early forms (see DZIK 1976; LOFGREN 1978) have rudimentary processes of tr and pI elements more prominently denticulated.

Autekologia

Występowanie geograficzne

Cosmopolitan species . 

Zasięg czasowy

In Mójcza from 2.2 m to 1.2 below the bentonite (E. robustus - E. lindstroemi Subzones).

Materiały muzealne

Literatura

Dzik, J. 1994a Conodonts of the Mójcza Limestone. In: J. Dzik, E. Olempska, & A. Pisera. Ordovician carbonate platform of the Holy Cross Mountains. Palaeontologia Polonica 53, 43-128.