Polygnathus webbi Stauffer, 1938 from the mid Frasnian of Wietrznia, late Frasnian of Wietrznia II quarry , lower cephalopod limestone at Płucki, latest Frasnian of Kowala  and Upper Kellwasserkalk at Płucki in the Holy Cross Mountains.

Diagnoza

The rostral margin of the platform is raised in the right P₁ element and caudal in the left; ornamentation variable.

Porównanie

In the early Frasnian populations of the lineage the platform of P₁ elements remains relatively narrow and robust, resembling the situation in the late Givetian. The range of variability, however, overlaps with morphologies typical of the late Frasnian. Somewhat above adult specimens with fusiform outline and relatively wide platform became more common. Assymetry and wide platform seem to develop late in ontogeny and then spread in the evolution to earlier and earlier developmental stages.

Autekologia

Występowanie geograficzne

Wietrznia, Kowala, Płucki.

Zasięg czasowy

Frasnian

Materiały muzealne

ZPAL

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.