| Leptophoca Temporal range: | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Carnivora |
| Clade: | Pinnipedia |
| Family: | Phocidae |
| Subfamily: | Phocinae |
| Genus: | † Leptophoca True, 1906 |
| Species | |
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Leptophoca is an extinct genus of earless seals from the North Atlantic realm.
Leptophoca lenis was coined by Frederick True for a humerus from the Calvert Formation of Maryland. [1] Later, Clayton Ray referred "Prophoca" proxima from the Antwerp region, Belgium, to Leptophoca. [2] A second nominal Leptophoca species, L. amphiatlantica, was coined for specimens found on both sides of the North Atlantic. [3] A 2017 study found proxima and lenis to be the same species, rendering proxima the epithet of the Leptophoca type species, but evidence for the validity of L. amphiatlantica was deemed weak, rendering amphiatlantica a nomen dubium within Leptophoca. [4]
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.
Fur seals are any of nine species of pinnipeds belonging to the subfamily Arctocephalinae in the family Otariidae. They are much more closely related to sea lions than true seals, and share with them external ears (pinnae), relatively long and muscular foreflippers, and the ability to walk on all fours. They are marked by their dense underfur, which made them a long-time object of commercial hunting. Eight species belong to the genus Arctocephalus and are found primarily in the Southern Hemisphere, while a ninth species also sometimes called fur seal, the Northern fur seal, belongs to a different genus and inhabits the North Pacific. The fur seals in Arctocephalus are more closely related to sea lions than they are to the Northern fur seal, but all three groups are more closely related to one another than they are to true seals.
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.
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.
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.
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.
Phocinae is a subfamily of Phocidae whose distribution is found in the seas surrounding the Holarctic, with the Baikal seal being the world's only freshwater species of pinniped. What distinguishes them from other phocid seals is the presence of well-developed claws on their front and back flippers. The Phocinae is divided into three extant tribes: Erignathini, Cystophorini, and Phocini. Members of both Erignathini and Cystophorini have 34 chromosomes, while species in the tribe Phocini have 32 chromosomes.
Monotherium is an extinct genus of phocid belonging to the subfamily Monachinae. It is known from fossils found in the middle to late Miocene of Belgium.
Pliophoca is an extinct genus of seal in the family Phocidae.
Nanophoca is an extinct genus of earless seals from the middle Miocene of Belgium.
Phocanella is an extinct genus of earless seals from the early Pliocene of Belgium and the US Eastern Seaboard.
Pontophoca is an extinct genus of earless seals from the middle-late Miocene of the eastern Paratethys basin and the North Sea.
Pachyphoca is an extinct genus of earless seals from Neogene marine deposits in the northern part of the Paratethys basin.
Platyphoca is an extinct genus of earless seals from Neogene marine deposits in the North Sea basin.
Praepusa is an extinct genus of earless seals from Neogene marine deposits in Europe. Five species, P. boeska,P. magyaricus, P. pannonica, P. tarchankutica and P. vindoboensis, are known.
Callophoca is an extinct genus of earless seals from the late Miocene to early Pliocene of Belgium and the US Eastern Seaboard.
Frisiphoca is an extinct genus of phocid belonging to the subfamily Phocinae. It is known from fossils found in the late Miocene of Belgium.
Auroraphoca is an extinct genus of earless seals from the early Pliocene of what is now the U.S. Eastern Seaboard.
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.
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