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 American plates. The ages of the earliest volcanic rocks from this plume lie in the late Paleocene, and both sides of the Atlantic Ocean contain these rocks. Since these rocks have been dated to the late Paleocene, this lines up with the time of breakup of the North Atlantic continent, so some think it could have been a contributing factor. This theory views volcanism as the resultant of lithospheric processes rather than heat from the mantle rising up. Instead of heat coming up from deep in the mantle, volcanic anomalies come from a shallow source. Volcanism thus occurs where the