Onega stepanovi placed in phylum Proarticulata, as the segments in recently discovered, exceptionally well-preserved fossils display the glide, or "staggered", symmetry characteristic of the majority of proarticulatans. Imprints of "Onega stepanovi" have been found in the Verkhovka and Zimnie Gory Formations of the Ediacaran (Vendian) rocks of the Arkhangelsk Region, Russia. All the fossil specimens are negative imprints on the bases of fine-grained sandstone beds with the "elephant skin" and tubercle texture diagnostic of microbial mats. The same bedding planes contain various other Ediacaran species: "Cyclomedusa", "Ediacaria", palaeopascichnids, "Eoporpita", "Yorgia", "Andiva", "Archaeaspinus", "Vendia", "Dickinsonia", "Anfesta", "Albumares", "Tribrachidium", "Kimberella", "Parvancorina", "Charniodiscus" and others.
Lake Onega Volga River, Caspian Sea and Black Sea. The Onega Canal, which follows the southern banks of the lake, was built in 1818–1820 and 1845–1852 between Vytegra River in the east and Svir River in the west. The canal was part of the Mariinsk Canal System, a forerunner of the Volga–Baltic Waterway, and aimed to create a quiet pass for boats avoiding the stormy waters of the lake. It is around wide, and lies between and from the shores of the lake. The canal is not used for active navigation at present. There are about 1650 islands in the lake with