Onega River traditionally explained as related to Finnish "Enojoki" - the main river, stream. In terms of both area of the basin and the average discharge, the Onega is the third river basin of the White Sea (behind the Northern Dvina and the Mezen. The river basin of the Onega is spread over the west of Arkhangelsk Oblast, north-west of Vologda Oblast, and also includes minor areas in the east of Republic of Karelia. The Onega basin includes some of the biggest lakes of Arkhangelsk and Vologda Oblasts, such as Lake Vozhe, Lake Lacha, Lake Lyokshmozero, Lake Kenozero, Lake Undozero, and Lake
Onega stepanovi by an undivided zone. The surface of the undivided region of "Onega" is covered with small tubercles. "Onega" was originally described by Mikhail Fedonkin as a problematic organism, being grouped together with "Vendia", "Praecambridium" and "Vendomia" as possible stem-group arthropods due to a vague similarity with primitive Cambrian trilobites and arthropods. In 1985 Mikhail Fedonkin erected Phylum Proarticulata, in which he placed: "Onega", "Dickinsonia", "Palaeoplatoda", "Vendia", "Vendomia", "Praecambridium" and "Pseudovendia sp.", although he did not exclude the possibility that "Onega" may still be related to various lower Cambrian arthropods, such as "Skania". Andrey Yu. Ivantsov has proposed that "Onega" be