''Potamotherium'' ('river beast') an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of caniform carnivoran from the

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

epoch of France and Germany. It has been previously assigned to the

mustelid The Mustelidae (; from Latin ''mustela'', weasel) are a family of carnivorous mammals, including weasels, badgers, otters, ferrets, martens, minks and wolverines, among others. Mustelids () are a diverse group and form the largest family in ...

family, but recent work suggests that it represents a primitive relative of

pinniped Pinnipeds (pronounced ), 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 (whose only living member is the walru ...

Classification

The genus was first described in 1833. Carroll (1988) assigned it to the family Mustelidae as a member of the subfamily

Oligobuninae ''Oligobuninae'' is an extinct subfamily of the family Mustelidae known from Miocene deposits in North America. The subfamily was described by J. A. Baskin in 1998; of the genera that he assigned to this clade, seven are recognized today - ''Bra ...

. However, it was recently suggested that ''Potamotherium'' was not a mustelid at all, but rather a very basal

. Berta et al. (2018) placed ''Potamotherium'' along with ''

Puijila ''Puijila darwini'' is an extinct species of stem-pinniped which lived during the Miocene epoch about 21 to 24 million years ago. Approximately a metre (three feet) in length, the animal possessed only minimal physical adaptations for swimming. U ...

'' and '' Semantor'' in the family Semantoridae. Two species have been identified in the genus: ''P. valletoni'', the type species, and ''P. miocenicum''.

Distribution

Finds range from the mid-latitudes of

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

and

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

, dated from the

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

boundary and surviving through to the end of the Miocene.Mörs, T. & Von Koenigswald, W. (2000): ''Potamotherium valletoni'' (Carnivora, Mammalia) aus dem Oberoligozän von Enspel im Westerwald. ''Senckenberg. Leth''. no 80: pp 257–273 It has been interpreted by several researchers as a basal, non-marine ancestor of

seals Seals may refer to: * Pinniped, a diverse group of semi-aquatic marine mammals, many of which are commonly called seals, particularly: ** Earless seal, or "true seal" ** Fur seal * Seal (emblem), a device to impress an emblem, used as a means of a ...

and sea lions, suggesting a freshwater phase in the evolutionary transition of pinnipeds from land to sea. If ''Potamotherium'' was indeed a pinniped instead of a mustelid, its relatives were possibly early

bear 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 Nor ...

s (whose ancestors at the time were small and generally weasel-like).

Palaeoecology

Physically, ''Potamotherium'' resembled a modern

otter Otters are carnivorous mammals in the subfamily Lutrinae. The 13 extant otter species are all semiaquatic, aquatic, or marine, with diets based on fish and invertebrates. Lutrinae is a branch of the Mustelidae family, which also includes wea ...

, and was long, with an elongated, slender body and short legs. With a flexible backbone and a streamlined shape, it was probably a good swimmer. Analysis of fossils suggests that ''Potamotherium'' had a poor sense of

smell Smell may refer to; * Odor, airborne molecules perceived as a scent or aroma * Sense of smell, the scent also known scientifically as olfaction * "Smells" (''Bottom''), an episode of ''Bottom'' * The Smell, a music venue in Los Angeles, Californ ...

, but made up for this with good vision and hearing.

References

{{Taxonbar, from=Q1636008 Miocene pinnipeds Miocene mammals of North America Aquitanian genus first appearances Tortonian extinctions Prehistoric pinnipeds of North America Miocene mammals of Europe Fossil taxa described in 1833 Prehistoric carnivoran genera