Bison is commonly known as American Buffalo which generally belongs from the species Bison roamed the grassland of North America becomes nearly extinct by Commercial hunting and slaughter and now we can see them at national park and reserves and in zoo. The two subspecies of bison is Wood Bison and Plain Bison.Plain bison are little smaller in size than the wood bison having a more rounded hump where the wood one have a large square hump. The wood bison is the largest wild animal of Bovid species and surpassed only by the Asian gaur and wild Asian water buffalo.But the American Buffalo differs from the European one. Where the American one have 15 ribs the European have 14. American buffalo has four lumbar vertebrae where the European has only 5. But they are superficially similar with each other.