Taxonomic revision and phylogenetic affinities of the conodont Bipennatus montensis (Weddige 1977) from the Eifelian (Middle Devonian) of Poland

摘要

Conodont investigations of the tetrapod-bearing lower Middle Devonian strata in the Holy Cross Mountains (SE Poland) furnished new data on morphological variability and phylogenetic affinities of the early bipennatid form, B. montensis (Weddige 1977), the latter raised herein to species level. B. montensis, and the genus Bipennatus in general, probably developed near the Emsian-Eifelian boundary from ozarkodinids showing an incipient median trough on the upper surface of the blade. In turn, Bipennatus montensis gave rise to B. bipennatus by a gradual development of nodose ridges on both sides of the trough.