Otarioidea is a superfamily of

pinniped Pinnipeds (pronounced ), commonly known as seals, are a widely range (biology), distributed and diverse clade of carnivorous, fin-footed, semiaquatic, mostly marine mammal, marine mammals. They comprise the extant taxon, extant family (biology ...

s that includes the families

Odobenidae Odobenidae is a family of pinnipeds. The only living species is the walrus (''Odobenus rosmarus''). In the past, however, the group was much more diverse, and includes more than a dozen fossil genera. Taxonomy All genera, except ''Odobenus'', ...

, Otariidae and their stem-relatives. In the past when the pinnipeds were considered to be a

diphyletic In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and most of its descendants, excluding a few monophyletic subgroups. The group is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

group of

marine mammal Marine mammals are aquatic mammals that rely on the ocean and other marine ecosystems for their existence. They include animals such as Pinniped, seals, Cetacea, whales, Sirenia, manatees, sea otters and polar bears. They are an informal group, ...

s, a few points of cranial and dental morphology suggested that the otarioids originated from a line of

bear Bears are carnivoran mammals of the family Ursidae. They are classified as caniforms, or doglike carnivorans. Although only eight species of bears are extant, they are widespread, appearing in a wide variety of habitats throughout the N ...

s. One extinct family, Enaliarctidae, was postulated to be otarioids that were a transitional clade between

Hemicyoninae Hemicyoninae is an extinct subfamily of Ursidae, often called dog bears (literally "half dog" (Greek: )). They were bear-like carnivorans living in Europe, North America, Africa and Asia during the Oligocene through Miocene epochs 33.9–5.3&nb ...

(an extinct subfamily of dog-like

s) and Otariidae. Recent comprehensive studies have, however, since the 1990s found pinnipeds to be a

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic ...

clade of aquatic arctoids. There are a few authorities that place desmatophocids and odobenids as sister taxa to Phocidae in the clade Phocomorpha based on a few minor physiological features.McKenna, Malcolm C., and Susan K. Bell (1997). ''Classification of Mammals Above the Species Level.'' New York: Columbia University Press. 631 pp.

References

{{Taxonbar, from=Q20721907 Pinnipeds Extant Burdigalian first appearances Taxa named by John Edward Gray