Arkhangelsk Oblast (the Northern Dvina), and the Mezen Bay (the Mezen and the Kuloy). Solovetsky Islands, as well as a number of smaller islands, are located in Onega Bay. Onega Bay and the Dvina Bay are separated by the Onega Peninsula. The Mezen Bay is separated from the main body of the White Sea by Morzhovets Island. Other major islands in the oblast include Shogly Island, Zhizgin Island, Yagry Island, Lyasomin Island, Layda Island, Nikolskiy Island, and Mudyugskiy Island. Almost all of the oblast is covered by taiga, the coniferous forest dominated by pine, spruce, and larch. Large areas in the middle
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.