The Turgai Strait, also known as the Turgay/Turgai Sea, Obik Sea, Ural Sea or West Siberian Sea, was a large shallow body of salt water during the Mesozoic through Cenozoic Eras. It extended north of the present-day Caspian Sea to the "paleo-Arctic" region, and was in existence from the Middle Jurassic to Oligocene, approximately 160 to 29 million years ago.