Atlantic Ocean encircled by the Gulf Stream, North Atlantic Drift, and North Equatorial Current. This population of seaweed probably originated from Tertiary ancestors on the European shores of the former Tethys Ocean and has, if so, maintained itself by vegetative growth, floating in the ocean for millions of years. Other species endemic to the Sargasso Sea include the sargassum fish, a predator with algae-like appendages who hovers motionless among the "Sargassum". Fossils of similar fishes have been found in fossil bays of the former Tethys Ocean, in what is now the Carpathian region, that were similar to the Sargasso Sea. It is
Opening of the North Atlantic Ocean The final major phase of breakup occurred in the early Cenozoic, as Laurentia separated from Eurasia. As the two plates broke free from each other, the Atlantic Ocean continued to expand. The Iceland plume is a mantle plume under Iceland that carries hot material from the deep within Earth's mantle upwards to the crust. The rising hot material weakens the lithosphere, making the separation of plates easier. The flow of hot plume material creates volcanism under the continental lithosphere. Iceland extends across the Mid-Atlantic Ridge. The Mid-Atlantic Ridge is a divergent plate boundary, and it separates the Eurasian and North