Desmatophocidae

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Desmatophocidae
Temporal range: Early to Late Miocene
Skeleton of Allodesmus.jpg
Skeleton of Allodesmus sp. at the National Museum of Nature and Science, Tokyo, Japan
Atopotarus courseni LACM 1376.jpg
Holotype skeleton of Atopotarus courseni at the Natural History Museum of Los Angeles County
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Clade: Pinnipedia
Superfamily: Otarioidea
Family: Desmatophocidae
Genera

Allodesmus
Atopotarus
Desmatophoca
Eodesmus

Desmatophocidae is an extinct family of pinnipeds closely related to either the eared seals and walruses [1] or to the earless seals. [2] [3] These animals were the first group of large-bodied pinnipeds to evolve, first appearing in the Early Miocene, with no direct modern descendants. [4] Desmatophocids have only been found to live in the North Pacific, with fossils being found in Baja California, California, Oregon, Washington, and Japan. [5]

The group is generally known for having large orbits, bulbous cheek teeth, and forelimbs similar to extant eared seals. [4]

Genera

Related Research Articles

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

Carnivora is an order of placental mammals that have specialized in primarily 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. These mammals have a large array of diverse body plans with a wide diversity of shapes and sizes.

<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">Walrus</span> Species of marine mammal with tusks

The walrus is a large pinniped marine mammal with discontinuous distribution about the North Pole in the Arctic Ocean and subarctic seas of the Northern Hemisphere. It is the only extant species in the family Odobenidae and genus Odobenus. This species is subdivided into two subspecies: the Atlantic walrus, which lives in the Atlantic Ocean, and the Pacific walrus, which lives in the Pacific Ocean.

<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">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">Flipper (anatomy)</span> Flattened limb adapted for propulsion and maneuvering in water

A flipper is a broad, flattened limb adapted for aquatic locomotion. It refers to the fully webbed, swimming appendages of aquatic vertebrates that are not fish.

<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">Ribbon seal</span> Species of mammal

The ribbon seal is a medium-sized pinniped from the true seal family (Phocidae). A seasonally ice-bound species, it is found in the Arctic and Subarctic regions of the North Pacific Ocean, notably in the Bering Sea and Sea of Okhotsk. It is distinguished by its striking coloration, with two wide white strips and two white circles against dark brown or black fur.

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>Desmatophoca</i> Extinct genus of carnivores

Desmatophoca is an extinct genus of early pinniped that lived during the Miocene, and is named from the Greek "phoca", meaning seal. A taxon of the family Desmatophocidae, it shares some morphological similarities with modern true seals. Two species are recognized: Desmatophoca oregonensis and Desmatophoca brachycephala. Little information exists regarding Desmatophoca, due to the small number of fossil samples obtained and identified.

<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 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.

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

Allodesmus is an extinct genus of pinniped from the middle to late Miocene of California and Japan that belongs to the extinct pinniped family Desmatophocidae.

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

Pelagiarctos was a genus of walrus that lived during the Mid Miocene, approx. 13-15 mya. Its remains have been found in the Sharktooth Hill Bonebed, in Kern County, California. It was originally described as an Otariidae, though it is now usually considered to be a basal Odobenidae.

Neotherium mirum is an extinct species of basal walrus. It was smaller than living forms and it did not have long tusks. Males were larger than females.

The Astoria Formation is a geologic formation in Washington state & Oregon. It preserves fossils dating back to the early to middle Miocene.

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

Pontolis is an extinct genus of large walrus. It contained three species, P. magnus, P. barroni, and P. kohnoi. Like all pinnipeds, Pontolis was a heavily built amphibious carnivore. Pontolis lived along the Pacific coast of North America along what is now the western coasts of California and Oregon between 11.608 and 5.332 million years ago, during the Miocene and Pliocene.

<i>Atopotarus</i> Extinct genus of carnivorans

Atopotarus is an extinct genus of pinniped from the middle Miocene known from one specimen from Los Angeles County, California. It belongs to the extinct family Desmatophocidae, an early lineage of seal-like pinnipeds from the North Pacific.

References

  1. Encyclopedia of Marine Mammals, ed. William F. Perrin, Bernd Würsig, J.G.M. Thewissen
  2. Park, T.; Burin, G.; et al. (1 July 2024). "Charting the course of pinniped evolution: insights from molecular phylogeny and fossil record integration". Evolution. 78 (7): 1212–1226. doi: 10.1093/evolut/qpae061 .
  3. Berta, Annelisa. "Encyclopedia of Marine Mammals, 2nd ed. Pinniped Evolution" (PDF). San Diego State University. Retrieved 1 September 2024.
  4. 1 2 Boessenecker, Robert W; Churchill, Morgan (2018-09-01). "The last of the desmatophocid seals: a new species of Allodesmus from the upper Miocene of Washington, USA, and a revision of the taxonomy of Desmatophocidae". Zoological Journal of the Linnean Society. 184 (1): 211–235. doi:10.1093/zoolinnean/zlx098. ISSN   0024-4082.
  5. Barnes, Lawrence G.; Hirota, Kiyoharu (1995). "Miocene pinnipeds of the otariid subfamily Allodesminae in the North Pacific Ocean: Systematics and relationships". The Island Arc. 3 (4): 329–360. doi:10.1111/j.1440-1738.1994.tb00119.x. ISSN   1038-4871.