Dvina Bay Dvina Bay The Dvina Bay () is located in Arkhangelsk Oblast in Northwestern Russia. It is one of four large bays and gulfs of the White Sea, the others being the Mezen Bay, the Onega Bay, and the Kandalaksha Gulf. The two main river emptying into the Dvina Bay is the Northern Dvina River, while the two cities on the bay are Arkhangelsk and Severodvinsk. The Dvina Bay is long and wide. Administratively, the coast and the islands belong to Primorsky District of Arkhangelsk Oblast. The Northern Dvina forms a delta entering the Dvina Bay, with many islands separating different
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.