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.
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.
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.
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.
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
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.
Pliopedia pacifica is an extinct species of walrus found in what is now Central Valley, California, United States, which lived during the late Miocene. It was an amphibious carnivore.
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.
Desmatophocidae is an extinct family of pinnipeds closely related to either the eared seals and walruses or to the earless seals. These animals were the first group of large-bodied pinnipeds to evolve, first appearing in the Early Miocene, with no direct modern descendants. Desmatophocids have only been found to live in the North Pacific, with fossils being found in Baja California, California, Oregon, Washington, and Japan.
The Astoria Formation is a geologic formation in Washington state & Oregon. It preserves fossils dating back to the early to middle Miocene.
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.
Pteronarctos is a genus of basal pinnipediform from middle Miocene marine deposits in Oregon.
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.
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.
Proneotherium is an extinct genus of pinniped that lived approximately 20.43 to 15.97 mya during the Early Miocene in what is now Oregon, U.S. It belonged to the family Odobenidae, the only extant species of which is the walrus.
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.
Otarioidea is a superfamily of pinnipeds that includes the families Odobenidae, Otariidae and their stem-relatives. In the past when the pinnipeds were considered to be a diphyletic group of marine mammals, a few points of cranial and dental morphology suggested that the otarioids originated from a line of bears. One extinct family, Enaliarctidae, was postulated to be otarioids that were a transitional clade between Hemicyoninae and Otariidae. Recent comprehensive studies have, however, since the 1990s found pinnipeds to be a 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.
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.
