Khanty Ocean
Khanty Ocean was an ancient, small ocean that existed near the end of the Precambrian time to the Silurian. It was between Baltica and the Siberian continent, with the bordering oceans of Panthalassa to the north, Proto-Tethys to the northeast, and Paleo-Tethys to the south and east. The ocean formed when a minor supercontinent of Proto-Laurasia (shortly after the break-up of Pannotia, about 600 mya) rifted and created three separated continents - Laurentia, Baltica, and Siberia, the ocean was between Siberia and Baltica. Khanty's sister ocean, Iapetus Ocean also formed, between Laurentia and Baltica. The ocean closed when an island arc called the Sakmarian Arc collided with Baltica. At the northeastern end of the arc was a new ocean, the Ural Ocean.