Marine fossils that are present in the Ural Mountains are as a result of formation through collision of two continents that are prehistoric. These are the Baltica and Siberia. The first step of the process that resulted in the marine fossils presence on the top of Ural Mountains started with lifting and separation of a single old continent into the two continents Baltica and Siberia. The rift went further and further apart leading to a fully fledged sea floor spreading. This created an ocean which was known as Palaeouralian Ocean.
During the time of existence of this ocean there were several kilometers of marine sediments along with the innumerable marine life congregated within it. Right from the late times of the Devonian period in the southern region and the early times of the carboniferous period in the northern region, this two continents Siberia and Baltica converged. This led to the squeezing and the uplifting of the crust and also the underlying sediments to the Palaeouralian Ocean. This initiated the formation of the Ural Mountains. By the mid periods of the carboniferous period, the collision of the two continents Baltica and Siberia led to the complete closure of the Palaeouralian Ocean.
This closure of this ocean compressed, then folded and henceforth uplifted the fossil bearing marine sediments. They accumulated and eventually turned into rock beneath the Palaeouralian Ocean leading to creation of Ural Mountains. As the process of uplifting the marine sediments continued to create Ural Mountains, the fossils contained in them were also uplifted and exposed on the summit as the sediments of the marine were eroded to the formation of the summit of the Ural Mountains.