Otarioidea

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Otarioids
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 Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Clade: Pinnipediformes
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 diphyletic group of marine mammals, based on the few cranial and dental morphology 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

Bear Family of mammals

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 Northern Hemisphere and partially in the Southern Hemisphere. Bears are found on the continents of North America, South America, Europe, and Asia. Common characteristics of modern bears include large bodies with stocky legs, long snouts, small rounded ears, shaggy hair, plantigrade paws with five nonretractile claws, and short tails.

Carnivora Order of mammals

Carnivora is an order of placental mammals that have specialized in primarily eating flesh. Its members are formally referred to as carnivorans, though some species are omnivorous, such as raccoons and bears, and quite a few species such as pandas are specialized herbivores. The word "carnivore" is derived from Latin carō "flesh" and vorāre "to devour" and refers to any meat-eating organism. The order Carnivora is the fifth largest order of mammals and one of the more successful members of the group, as it comprises at least 279 species.

Earless seal 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.

Eared seal Marine mammals in the family Otariidae

An eared seal or 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 and the southern Indian and Atlantic Oceans. They are conspicuously absent in the north Atlantic.

Marine mammal Mammals that rely on marine environments for feeding

Marine mammals are aquatic mammals that rely on the ocean and other marine ecosystems for their existence. They include animals such as seals, whales, manatees, sea otters and polar bears. They are an informal group, unified only by their reliance on marine environments for feeding and survival.

Pinniped Infraorder of mammals

Pinnipeds, commonly known as seals, are a widely distributed and diverse clade of carnivorous, fin-footed, semiaquatic marine mammals. They comprise the extant families Odobenidae, Otariidae, and Phocidae. There are 33 extant species of pinnipeds, and more than 50 extinct species have been described from fossils. While seals were historically thought to have descended from two ancestral lines, molecular evidence supports them as a monophyletic lineage. Pinnipeds belong to the order Carnivora and their closest living relatives are bears and the superfamily of musteloids, having diverged about 50 million years ago.

Sauropsida taxonomic clade.

Sauropsida is a clade of amniotes, broadly equivalent to the class Reptilia. Sauropsida is the sister taxon to Synapsida, the clade of amniotes which includes mammals as its only modern representatives. Although early synapsids have historically been referred to as "mammal-like reptiles," all synapsids are more closely related to mammals than to any modern reptile. Sauropsids, on the other hand, include all amniotes more closely related to modern reptiles than to mammals. This includes Aves (birds), which are now recognized as a subgroup of archosaurian reptiles despite originally being named as a separate class in Linnaean taxonomy.

Caniformia Suborder of carnivores

Caniformia is a suborder within the order Carnivora consisting of "dog-like" carnivorans. They include dogs, bears, wolves, foxes, raccoons, badgers, 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.

Potamotherium an extinct genus of caniform carnivoran from the Miocene epoch of France and Germany. It has been previously assigned to the mustelid family, but recent work suggests that it represents a primitive relative of pinnipeds.

<i>Enaliarctos</i> Genus of pinniped

Enaliarctos is an extinct genus of pinniped, and may represent the ancestor to all pinnipeds. Prior to the discovery of Puijila, the five species in the genus Enaliarctos represented the oldest known pinniped fossils, having been recovered from late Oligocene and early Miocene strata of California and Oregon.

In phylogenetics, basal is the direction of the base of a rooted phylogenetic tree or cladogram. The term may be more strictly applied only to nodes adjacent to the root, or more loosely applied to nodes regarded as being close to the root. Each node in the tree corresponds to a clade; i.e., clade C may be described as basal within a larger clade D if its root is directly linked to the root of D. The terms deep-branching or early-branching are similar in meaning.

Parictis is an extinct arctoid. Possibly the earliest genus of bears known. Though recent a variety of morphological evidence links amphicynodontines with pinnipeds. It was a very small and graceful arctoid with a skull only 7 cm long. Parictis first appeared in North America in the Late Eocene, but it did not arrive in Eurasia until the Miocene. Some suggest that Parictis may have emigrated from Asia into North America during the major sea level low about 37 mya, because of the continued evolution of the Amphicynodontinae into the Hemicyoninae in Asia. Although no Parictis fossils have been found in East Asia, Parictis does appear in Eurasia and Africa, but not until the Miocene.

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

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 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.

Oligobuninae Extinct subfamily of carnivores

Oligobuninae is an extinct subfamily of the family Mustelidae known from Miocene deposits in North America.

Amphicynodontinae Extinct clade of carnivores

Amphicynodontinae 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.

Semantoridae Extinct family of carnivores

Semantoridae is an extinct family of stem-pinnipeds with fossils found in France, Kazakhstan, and Canada, dating back to various points in time in the Miocene epoch. Based on their overall anatomy semantorids were not marine specialists, as their elongated bodies, a long tail and robust limbs suggest they were freshwater animals not unlike otters. Indeed, at least some taxa such as Semantor and Potamotherium were initially classified as mustelids closely related to otters.

Pinnipedimorpha Extinct clade of carnivores

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

Monachinae 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.

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). "Pinniped taxonomy: review of currently recognized species and subspecies, and evidence used for their description". 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