WHAT ARE THE UNGULATES?
The word 'ungulate' comes from the Latin
'ungula', meaning hoof. It has long been used
as a term to describe any hooved herbivorous mammal, but the ungulates have not been
thought to constitute a single group of closely related animals until recently. The
'ungulates' were considered to comprise the Artiodactyla (even-toed ungulates like pigs
or cattle), the Perissodactyla (odd-toed ungulates like horses or tapirs) and various
fossil groups of primitive ungulates. The aardvark, elephants and hyraxes were referred
to as 'subungulates'.
Today, the 'Ungulata' is believed to contain 6, perhaps 7 living
(even-toed ungulates eg.
pigs, camels, deer and cattle).
(odd-toed ungulates eg.
horses, tapirs and rhinoceroses).
The Order HYRACOIDEA
The Order CETACEA
(whales and dolphins).
Strange as it may seem, whales are ungulates...
There are also several orders of
'Ungulate' is a much abused term. The zoologist Alfred Sherwood Romer
noted that "almost all the larger herbivorous members of the class [Mammalia]" may be
ranged under the term, but he acknowledged that this may include several independently
evolving lineages. This rather broad definition of ungulate contrasts with the
traditionally narrow definition of 'Ungulata', which included only the Artiodactyla
and the Perissodactyla.
All the orders listed above have recently been shown to have
all come from a common ancestor, separate from other mammal groups. The earliest
ungulate known is Protungulatum,
from the Late cretaceous of North America. It was a small, insectivore-like animal
with teeth slightly adapted for grinding.
The skull of