Onega stepanovi Onega stepanovi Onega stepanovi is a fossil organism from Ediacaran deposites of the Arkhangelsk Region, Russia. It was described by Mikhail A. Fedonkin in 1976 The generic name "Onega" comes from the Onega Peninsula of the White Sea, where the first fossils were found. The specific name is given in honour of V. A. Stepanov, discoverer of the first Ediacaran fossil locality in Arkhangelsk Region, on the Letniy Bereg (Summer Coast) of the Onega Peninsula in 1972. The small fossils, which range up to long, have oval outlines and low bodies with an articulated central zone built of isomers encircled
Lake Onega the last Ice Age, about 12,000 years ago: In the Paleozoic Era (400–300 million years ago) the entire territory of the modern basin of the lake was covered with a shelf sea lying near the ancient, near-equatoric Baltic continent. Sediments at that time – sandstone, sand, clay and limestone – form a layer covering the Baltic Shield which consists of granite, gneiss and greenstone. The retreat of the Ice Age glaciers formed the Littorina Sea. Its level was first higher than at present, but it gradually lowered, thereby decreasing the sea area and forming several lakes in the Baltic region.