Why don't the present shapes of the continents fit perfectly into a supercontinent?

The reason why the shapes of the continents as of today do not perfectly fi into to super continent because long time ago the super continent was scattered into pieces. And as times go by, those smaller parts of super continents undergo soil erosion caused by the water and other way that causes their original shapes change. 

Because electrons have negligible mass, to account for the mass of the isotope, there must be 16 neutrons, 16 neutrally charged, massive, fundamental particles present in the sulfur nucleus. and thus finally, if we have the 32s2− ion, there are 18 electrons, 16 protons, and 16 neutrons.

Its trait is different and it the organism survive