Fig. 4. A in A new Metapolygnathus platform conodont species and its implications for Upper Carnian global correlations

Fig. 4. A schematic figure illustrating the evolution of Paragondolella noah (Hayashi, 1968) into its descendant species. The main evolutionary trends from P. noah to the last representative of the lineage, Metapolygnathus parvus Kozur, 1972, are observable: the gradual shortening of the platform, the forward shifting of the pit, the posterior lengthening of the keel termination and the development of nodes at the geniculation point. In M. parvus the nodes disappear for the extreme reduction of the platform. A, B. Metapolygnathus parvus Kozur, 1972 (sample NA37, Lower Norian, PMs). C, D. Metapolygnathus communisti Hayashi, 1968 (samples NA39 and PM27 respectively, Lower Norian, PMs). Metapolygnathus praecommunisti sp. nov. from the Upper Carnian of the PMs and P2s: E, F. Very advanced specimens (samples NA22 and NA19 respectively, PMs). G, H. Intermediate specimens (samples NA12 and NA14 respectively, PMs). I, J. Primitive specimens (sample P25 of P2s and sample NA8 of PMs respectively). K, L. Paragondolella noah (sample NA2 of PMs and sample P21 of P2s respectively). Abbreviations: PMs, Pizzo Mondello section; P2s, Pignola 2 section.