Older oceanic crust, which is more dense than continental crust, has long since been recycled in the process of subduction. Credit: U.S. Geological Survey. Plate tectonics shapes the surface of our planet, but it also runs much deeper: Plate movement is the surface expression of convection in Earth's interior.
I think the answer is Specialized cells!
Bipedalism is a form of terrestrial locomotion where an organism moves by means of its two rear limbs or legs.
(ostrich, human etc. )
