What characteristics led camels to be classified in the same domain kingdom phylum and class as dogs?

Camels and dogs are both members of the Domain Eukarya, Kingdom Animalia, Phylum Chordata, and Class Animalia. Here are the characteristics that led camels to be classified in the same domain kingdom phylum and class as dogs:

The camels are classified as mammals same with dogs. Camels and dogs both have four legs and they have a spinal cord, too. As mammals, camels have hair, mammary glands just like dogs. They give birth and their young drink milk when they are babies just like the dogs also.