Otarioidea

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Otarioidea
Temporal range: OligoceneHolocene, 24–0  Ma
Walrus2.jpg
A rookery of walruses (Odobenus rosmarus)
Southern Sea Lions.jpg
A male and female South American sea lion (Otaria flavescens)
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Clade: Pinnipedia
Superfamily: Otarioidea
J. E. Gray, 1821
Subclades

Otarioidea is a superfamily of pinnipeds that includes the families Odobenidae, Otariidae and their stem-relatives. [1] [2] In the past when the pinnipeds were considered to be a polyphyletic group of marine mammals, a few points of cranial and dental morphology suggested that the otarioids originated from a line of bears. [3] One extinct family, Enaliarctidae, was postulated to be otarioids that were a transitional clade between Hemicyoninae (an extinct subfamily of dog-like bears) and Otariidae. [3] Recent comprehensive studies have, however, since the 1990s found pinnipeds to be a monophyletic clade of aquatic arctoids. [1] 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. [4]

Related Research Articles

<span class="mw-page-title-main">Carnivora</span> Order of mammals

Carnivora is an order of placental mammals specialized primarily in eating flesh, whose members are formally referred to as carnivorans. The order Carnivora is the sixth largest order of mammals, comprising at least 279 species on every major landmass and in a variety of habitats, ranging from the cold polar regions of Earth to the hyper-arid region of the Sahara Desert and the open seas. Carnivorans exhibit a wide array of body plans, varying greatly in size and shape.

<span class="mw-page-title-main">Earless seal</span> Family of mammals

The earless seals, phocids, or true seals are one of the three main groups of mammals within the seal lineage, Pinnipedia. All true seals are members of the family Phocidae. They are sometimes called crawling seals to distinguish them from the fur seals and sea lions of the family Otariidae. Seals live in the oceans of both hemispheres and, with the exception of the more tropical monk seals, are mostly confined to polar, subpolar, and temperate climates. The Baikal seal is the only species of exclusively freshwater seal.

<span class="mw-page-title-main">Ungulate</span> Group of animals that walk on the tips of their toes or hooves

Ungulates are members of the diverse clade Euungulata, which primarily consists of large mammals with hooves. Once part of the clade "Ungulata" along with the clade Paenungulata, "Ungulata" has since been determined to be a polyphyletic and thereby invalid clade based on molecular data. As a result, true ungulates had since been reclassified to the newer clade Euungulata in 2001 within the clade Laurasiatheria while Paenungulata has been reclassified to a distant clade Afrotheria. Living ungulates are divided into two orders: Perissodactyla including equines, rhinoceroses, and tapirs; and Artiodactyla including cattle, antelope, pigs, giraffes, camels, sheep, deer, and hippopotamuses, among others. Cetaceans such as whales, dolphins, and porpoises are also classified as artiodactyls, although they do not have hooves. Most terrestrial ungulates use the hoofed tips of their toes to support their body weight while standing or moving. Two other orders of ungulates, Notoungulata and Litopterna, both native to South America, became extinct at the end of the Pleistocene, around 12,000 years ago.

<span class="mw-page-title-main">Eared seal</span> Family of marine mammals

An eared seal, otariid, or otary is any member of the marine mammal family Otariidae, one of three groupings of pinnipeds. They comprise 15 extant species in seven genera and are commonly known either as sea lions or fur seals, distinct from true seals (phocids) and the walrus (odobenids). Otariids are adapted to a semiaquatic lifestyle, feeding and migrating in the water, but breeding and resting on land or ice. They reside in subpolar, temperate, and equatorial waters throughout the Pacific and Southern Oceans, the southern Indian, and Atlantic Oceans. They are conspicuously absent in the north Atlantic.

<span class="mw-page-title-main">Marine mammal</span> Mammals that rely on marine environments for feeding

Marine mammals are mammals that rely on marine (saltwater) ecosystems for their existence. They include animals such as cetaceans, pinnipeds, sirenians, sea otters and polar bears. They are an informal group, unified only by their reliance on marine environments for feeding and survival.

<span class="mw-page-title-main">Pinniped</span> Taxonomic group of semi-aquatic mammals

Pinnipeds, commonly known as seals, are a widely distributed and diverse clade of carnivorous, fin-footed, semiaquatic, mostly marine mammals. They comprise the extant families Odobenidae, Otariidae, and Phocidae, with 34 extant species and more than 50 extinct species described from fossils. While seals were historically thought to have descended from two ancestral lines, molecular evidence supports them as a monophyletic group. Pinnipeds belong to the suborder Caniformia of the order Carnivora; their closest living relatives are musteloids, having diverged about 50 million years ago.

<span class="mw-page-title-main">Amniote</span> Clade of tetrapods including reptiles, birds and mammals

Amniotes are tetrapod vertebrate animals belonging to the clade Amniota, a large group that comprises the vast majority of living terrestrial and semiaquatic vertebrates. Amniotes evolved from amphibious stem tetrapod ancestors during the Carboniferous period. Those of Amniota are defined as the smallest crown clade containing humans, the Greek tortoise, and the Nile crocodile.

<span class="mw-page-title-main">Bearded seal</span> Species of Arctic dwelling marine mammal

The bearded seal, also called the square flipper seal, is a medium-sized pinniped that is found in and near to the Arctic Ocean. It gets its generic name from two Greek words that refer to its heavy jaw. The other part of its Linnaean name means bearded and refers to its most characteristic feature, the conspicuous and very abundant whiskers. When dry, these whiskers curl very elegantly, giving the bearded seal a "raffish" look.

<span class="mw-page-title-main">Caniformia</span> Suborder of mammals

Caniformia is a suborder within the order Carnivora consisting of "dog-like" carnivorans. They include dogs, bears, raccoons, and mustelids. The Pinnipedia are also assigned to this group. The center of diversification for the Caniformia is North America and northern Eurasia. Caniformia stands in contrast to the other suborder of Carnivora, the Feliformia, the center of diversification of which was in Africa and southern Asia.

<span class="mw-page-title-main">South American native ungulates</span> Extinct clade of mammals

South American native ungulates, commonly abbreviated as SANUs, are extinct ungulate-like mammals that were indigenous to South America from the Paleocene until the end of the Late Pleistocene. They represented a dominant element of South America's Cenozoic terrestrial mammal fauna prior to the arrival of living unguate groups in South America during the Pliocene and Pleistocene as part of the Great American Interchange. They comprise five major groups conventionally ranked as orders—Astrapotheria, Litopterna, Notoungulata, Pyrotheria, and Xenungulata—as well as the primitive "condylarth" groups Didolodontidae and Kollpaniinae. It has been proposed that some or all of the members of this group form a clade, named Meridiungulata, though the relationships of South American ungulates remain largely unresolved. The two largest groups of South American ungulates, the notoungulates and the litopterns, were the only groups to persist beyond the mid Miocene. Only a few species of notoungulates and litopterns survived until the end-Pleistocene extinction event around 12,000 years ago where they became extinct with most other large mammals in the Americas, shortly after the first arrival of humans into the region.

<span class="mw-page-title-main">Neognathae</span> Infraclass of birds

Neognathae is an infraclass of birds, called neognaths, within the class Aves of the clade Archosauria. Neognathae includes the majority of living birds; the exceptions being the tinamous and the flightless ratites, which belong instead to the sister taxon Palaeognathae. There are nearly 10,000 living species of neognaths.

Potamotherium an extinct genus of caniform carnivoran from the Miocene epoch of France and Germany. It has historically been assigned to the family Mustelidae, but more recent studies suggest that it represents a primitive relative of pinnipeds

<i>Enaliarctos</i> Genus of pinniped

Enaliarctos is an extinct genus of pinnipedimorph, and may represent the ancestor to all pinnipeds. The five species in the genus Enaliarctos have been recovered from late Oligocene and early Miocene strata of California and Oregon.

<span class="mw-page-title-main">Ursoidea</span> Superfamily of mammals

Ursoidea is a superfamily of arctoid carnivoran mammals that includes the families Subparictidae, Amphicynodontidae, and Ursidae. The last family includes the extant lineages of bears, as well as the extinct Hemicyoninae and Ursavinae.

<i>Kolponomos</i> Extinct genus of mammals

Kolponomos is an extinct genus of carnivoran mammal that existed in the Late Arikareean North American Land Mammal Age, early Miocene epoch, about 20 million years ago. It was likely a marine mammal. The genus was erected in 1960 by Ruben A. Stirton, a paleontologist at the University of California Museum of Paleontology, Berkeley, for the species K. clallamensis, on the basis of a partial skull and jaw found on the Clallam Formation of the Olympic Peninsula. At the time, Stirton questionably assigned it to Procyonidae, its systematic position remained problematic until the discovery of more fossils including a nearly complete cranium from the original locality of K. clallamensis which helped identify it as part of the group from which pinnipeds evolved.

<span class="mw-page-title-main">Amphicynodontidae</span> Extinct clade of mammals

Amphicynodontidae is a probable clade of extinct arctoids. While some researchers consider this group to be an extinct subfamily of bears, a variety of morphological evidence links amphicynodontines with pinnipeds, as the group were semi-aquatic otter-like mammals. In addition to the support of the pinniped–amphicynodontine clade, other morphological and some molecular analyses support bears being the closest living relatives to pinnipeds. According to McKenna and Bell (1997) Amphicynodontinae are classified as stem-pinnipeds in the superfamily Phocoidea. Fossils of these mammals have been found in Europe, North America and Asia. Amphicynodontines should not be confused with Amphicyonids (bear-dogs), a separate family of Carnivora which is a sister clade to arctoids within the caniforms, but which may be listed as a clade of extinct arctoids in older publications.

<i>Prototaria</i> Extinct genus of pinniped

Prototaria is an extinct genus of pinniped that lived approximately 15.97 to 13.65 mya during the Middle Miocene in what is now Japan. It belonged to the family Odobenidae, the only extant species of which is the walrus. Members of the genus Prototaria are believed to be the most basal imagotariine pinnipeds.

<span class="mw-page-title-main">Pinnipedimorpha</span> Stem-clade of arctoid carnivorans

Pinnipedimorpha is a clade of arctoid carnivorans that is defined to include the last common ancestor of Phoca and Enaliarctos, and all descendants of that ancestor. Scientists still debate on which lineage of arctoid carnivorans are the closest relatives to the pinnipedimorphs, being more closely related to musteloids.

<span class="mw-page-title-main">Monachinae</span> Subfamily of carnivores

Monachinae is a subfamily of Phocidae whose distribution is found in the tropical, temperate and polar regions of the southern hemisphere, though in the distant past fossil representatives have been found on both sides of the North Atlantic Ocean. The difference between members of this group and members of Phocinae is in monachines the hindclaws are greatly reduced in size. Furthermore, all species have 34 chromosomes. There are three tribes recognized here: Monachini, Miroungini, and Lobodontini. While today represented by eight extant and one recently extinct species, Monachinae had an incredibly enriched fossil diversity that went into decline soon to be replaced by southern species of sea lions and fur seals.

Subparictidae is an extinct family of early Paleogene arctoid carnivorans endemic to North America that closely related to bears. They were small, raccoon-like mammals that lived from the Eocene to the early Miocene. This family includes a handful of genera such as Subparictis, Parictis, Nothocyon, and Eoarctos.

References

  1. 1 2 Berta, A.; Churchill, M. & Boessenecker, R.W. (2018). "The Origin and Evolutionary Biology of Pinnipeds: Seals, Sea Lions, and Walruses". Annual Review of Earth and Planetary Sciences. 46: 203–228. Bibcode:2018AREPS..46..203B. doi: 10.1146/annurev-earth-082517-010009 .
  2. Paterson, R. S.; Rybczynski, N.; Kohno, N.; Maddin, H. C. (2020). "A Total Evidence Phylogenetic Analysis of Pinniped Phylogeny and the Possibility of Parallel Evolution Within a Monophyletic Framework". Frontiers in Ecology and Evolution. 7 (457). doi: 10.3389/fevo.2019.00457 .
  3. 1 2 Mitchell, E. & Tedford, R. H. (1973). "The Enaliarctinae: a new group of extinct aquatic Carnivora and a consideration of the origin of the Otariidae". Bulletin of the AMNH. 151 (3). hdl:2246/1178.
  4. McKenna, Malcolm C., and Susan K. Bell (1997). Classification of Mammals Above the Species Level. New York: Columbia University Press. 631 pp. ISBN   0-231-11013-8