The Ural Mountains are found at the Eastern boundary of the European part of Russia and they mark the geologic and natural topographic border between Asia and Europe. The collisions between "Baltica" and "Siberia" which are two prehistoric continents led to the formation and presence of marine fossils in the Ural Mountains. During the fossil formation process on top of the mountains, the first step involved the rifting and separation of Baltica, the old continent into Siberia.
The rift continued to expand and progressed into a fully fledged seafloor spreading which led to the formation of an ancient ocean referred to as the Palaeouralian Ocean during the periods referred to as Late Cambrian-Lower Ordovician periods. As the ocean continued to exist, many kilometers of sediments and the remains of the innumerable marine creatures that were living in the ocean accumulated in the ocean.
During the early Carboniferous period in the north and late Devonian period in the south, the two continents, Siberia and Baltica started to converge/moving close to each other. They squeezed together leading to the uplifting of the sediments and crusts that were in the Palaeouralian Ocean to facilitate the formation of the Ural Mountains. Then, the ocean's closure compressed, faulted, folded and the fossil bearing marine sediments that were uplifted earlier accumulated and made the rocks beneath the Palaeouralian Ocean to become the Ural Mountains.
At the time when the marine sediments from the ocean were uplifted to form the Ural Mountains, the fossils that were found in the sediments were also uplifted and they remained exposed as the other marine sediments were eroded from the summits of the mountains. The fossils on the Ural Mountains include fish, shelled creatures and the microbial bound stones which are sponges that make up a barrier reef that is seen on the sea floor.