) are a diverse group of large mammals
, most of which use the tips of their toes, usually hoofed, to sustain their whole body weight while moving. The term means, roughly, "being hoofed
" or "hoofed animal". As a descriptive term, "ungulate" normally excludes cetaceans
, as they do not possess most of the typical morphological characteristics of ungulates; recent discoveries indicate that they are descended from early artiodactyls
, and thus are directly related to other even-toed ungulates
such as cattle, with hippopotamuses
being their closest living relatives.
As a result of these discoveries, the new order Cetartiodactyla
has been proposed to include the members of Artiodactyla
, to reflect their common ancestry; however, strictly speaking, this is merely a matter of nomenclature, since it is possible simply to recognize Cetacea as a subgroup of Artiodactyla.