Steven Parks, age 10, of Eugene, Ore., or his question:

Is the rhinoceros related to the horse?

The horse and the rhino are both mammals, but this does not make them related to each other. They both belong to the order of ungulate animals, because they walk on hooves and eat only vegetables. Even this does not make them close relatives. Actually the horse belongs to one family of ungulates and the rhinoceros belongs to another.

All members of the horse family are related to each other, somewhat like first cousins. There are only three different rhinos in the world, and these cousins have a whole animal family to themselves. As you would expect, there are family resemblances in animals that are related to each other. The rhinos do not resemble the horses at all. Even though they are both classed as ungulate animals, the two families are not related.