Francodina santacrucensis (Dzik, 2006) from the K. crepida Zone at Jabłonna (bed 8) in the Holy Cross Mountains.

Apparatus composition of Francodina santacrucensis

Diagnoza

S elements with processes emerging under a wide angle.

Porównanie

Unlike the probably related species of Vogelgnathus, elements of F. santacrucensis are of large size, even as compared with the largest known conodonts of the Famennian. There seems to be an increase in mature size in the evolution of the lineage, probably a reversal from the tendency to paedomorphism, which was probably behind the origin of the branch of francodinids. Pandorinellina? vogelgnathoides sp. n. is somewhat similar to this oldest Francodina in showing a tendency to bifurcation of the external process of S₁ elements and arched contour of P₁ elements. Its S elements, however, are still of a rather generalized polygnathid appearance and the species is known from significantly younger strata.

Autekologia

Występowanie geograficzne

Jabłonna, Wietrznia, and Kadzielnia.

Zasięg czasowy

K. crepida Zone.  

Materiały muzealne

ZPAL: 1,121 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.