term "pinniped' derives from the Latin word "pinna",
meaning, wing or feather, and "pedis", meaning foot.
Pinnipeds are amphibious, aquatic marine carnivores whose front
and hind limbs are flippers. All pinnipeds had to modify the
basic mammalian pattern, which is designed for life on land,
into a body form adapted to life in the three dimensional environment
of water. In order to thrive in an aquatic environment, pinnipeds
had to evolve physiological and structural alterations to permit
movement in a three-dimensional water environment, to prevent
loss of heat in the cooler water, and to develop a suite of
adaptations associated with maintaining activity while ventilating
the lungs relatively infrequently - the whole comprising the
physiology of diving. There were three generally recognized
families in the Pinnipedia: Phocidae (true seals), Otariidae
(eared seals), and Odobenidae (walruses).
also spend considerable time on land along the arctic and subarctic
shores of all the world's oceans (in contrast to the cetaceans
and sirenians, which are completely aquatic). These shore activities
include resting and sleeping, temperature regulation, as well
as mating, giving birth, and nursing the young.
Pinnipedia include three families: the Odobenidae, which today
has only a single species, the walrus: the Otariidae, the eared
seals, containing 14 species, and the Phocidae, the true seals,
with 18 species. The similarities between the Odobenidae and
the Otariidae are sufficient to justify combining them into
a superfamily: the Otarioidea. It is possible that these two
groups arose separately from the carnivore stock; the eared
seals about 25 million years ago and true seals about 15 million
years ago. The degree of relationship between pinnipeds and
carnivores has been a matter of debate.
Pinnepeds in our collections include the following specimens:
Otariidae (Formerly Pinnepedia)
"Walker's Mammals of the World" (fifth edition), by
Ronald M. Nowak, Published in 1991 in Baltimore and London by
the Johns Hopkins University Press.