Geology of the Pacific Ocean Geology of the Pacific Ocean The Pacific Ocean evolved in the Mesozoic from the Panthalassic Ocean, which had formed when Rodinia rifted apart around 750 Ma. The first ocean floor which is part of the current Pacific Plate began 160 Ma to the west of the central Pacific and subsequently developed into the largest oceanic plate on Earth. The tectonic plates continue to move today. The slowest spreading ridge is the Gakkel Ridge on the Arctic Ocean floor, which spreads at less than , while the fastest, the East Pacific Rise near Easter Island, has a spreading rate of over
Largest organisms living mammals. Since no scale can accommodate the whole body of a large whale, most whales have been weighed by parts. The following is a list of the heaviest wild land animals, which are all mammals. The African elephant is now listed as two species, the African bush elephant and the African forest elephant, as they are now generally considered to be two separate species. The largest tunicates are "Synoicum pulmonaria", found at depths of , and are up to 14 centimetres (6 in) in diameter. It is also present in the northwestern Atlantic Ocean, around the coasts of Greenland