Cetartiodactyla is the taxonomical superorder which includes whales (and dolphins) and even-toed ungulates. The name was created by merging the name for the two orders, Cetacea and Artiodactyla, into a single word.
Cetartiodactyla is used because it is thought that whales evolved from the artiodactyls. Because of this, their closest living land relative may be the hippopotamus.