New data on conodonts from the Kasimovian Stage of the Usolka section, southern Ural Mountains

© 2015, Pleiades Publishing, Ltd. Conodonts from the Moscovian–Kasimovian boundary beds of the Usolka section (southern Ural Mountains) are studied. Morphological features of conodont elements are analyzed and the main taxonomically significant characters of conodonts from the Moscovian–Kasimovian boundary are revealed. These characters are intended for the establishment of reliable determination of index species of the lower boundary of the Kasimovian Stage of the International Stratigraphic Chart. The most promising species marking this border is apparently “Streptognathodus” subexcelsus Alekseev et Goreva