The study of the material from the Upper Carnian of Northern Kharalukah and the upper reaches of the Adycha River basin allowed us to clarify the species composition of the genera Yakutosirenites Tozer, 1994 and Orientosirenites Konstantinov, 2018. Based on the study of the shell shape, sculpture and lobe line features, the identification of new species Yakutosirenites (Yakutosirenites) selivanovae sp. nov. and Orientosirenites insolitus sp. nov. was substantiated. Their description is given. The new data allow us to supplement the taxonomic composition of the late Carnian ammonoids of Eastern Yakutia.
A.G. Konstantinov (Wed,) studied this question.