The probable reason for the case would be that the sea floor 200 million years ago is now above the sea level.
The ocean floor is the eventual recycling center. While the Earth's continental crust can prevail for billions of years, the movement of tectonic plates results in subduction, that is when the crust of the ocean is pushed down into the present mantle. So, the ocean floor hardly endures longer than 200 million years.
<span>They destroy pathogens that enter the wound. This obliteration of any pathogens is called phagocytosis. A white platelet ingesting infection creating microorganisms. White platelets can: ingest pathogens and devastate them. deliver antibodies to demolish specific pathogens.</span>