''Amphiperatherium'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

metatheria Metatheria is a mammalian clade that includes all mammals more closely related to marsupials than to placentals. First proposed by Thomas Henry Huxley in 1880, it is a more inclusive group than the marsupials; it contains all marsupials as we ...

n mammal, closely related to

marsupial Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a ...

s. It ranged from the Early

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

to the Middle

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 recent" ...

in Europe. It is the most recent metatherian known from the continent.

Description

Like modern

opossum Opossums () are members of the marsupial order Didelphimorphia () endemic to the Americas. The largest order of marsupials in the Western Hemisphere, it comprises 93 species in 18 genera. Opossums originated in South America and entered Nort ...

s, to which it was distantly related, this animal had a 15 centimeters long body and a 17 centimeters long tail. Its body size was relatively larger than some of its earlier relatives, such as ''

Peradectes ''Peradectes'' is an extinct genus of small metatherian mammals known from the CretaceousKorth, W. W. (2008). Marsupialia. In C. M. Janis, G. F. Gunnell, & M. D. Uhen (Eds.)Evolution of Tertiary Mammals of North America: Volume 2, Small Mammals, ...

'', but its tail was proportionally shorter.

Classification

''Amphiperatherium'' is part of an evolutionary radiation of opossum-like metatherians, known as

Herpetotheriidae Herpetotheriidae is an extinct family of metatherians, closely related to marsupials. Species of this family are generally reconstructed as terrestrial, and are considered morphologically similar to modern opossums. Fossils of herpetotheriids com ...

, typical of the Early

Cenozoic The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configu ...

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 subcontinent of Eurasia and it is located enti ...

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an ...

and North America, currently considered either the most primitive of all marsupials, or the sister taxa of

Marsupialia Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a ...

. ''Amphiperatherium'' was not only the more recent herpetotheriid known, but also the last marsupial known in Europe, becoming extinct during the Middle Miocene, 15 millions of years ago. Its extinction coincided with a general cooling of the European climate, which seems to have been the fatal blow for the herpetotheriids, adapted to milder climates. The genus was first described by Filhol in 1879, based on material found in

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan ar ...

, but additional fossils were later found in

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = '' Plus ultra'' ( Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , ...

Germany Germany, officially the Federal Republic of Germany (FRG),, is a country in Central Europe. It is the most populous member state of the European Union. Germany lies between the Baltic and North Sea to the north and the Alps to the sou ...

Belgium Belgium, ; french: Belgique ; german: Belgien officially the Kingdom of Belgium, is a country in Northwestern Europe. The country is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to ...

Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. Th ...

and

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe ...

, the genus surviving for 35 millions of years, from the Early Eocene to the Late Miocene. ''Amphiperatherium'' must have been an evolutionary success, allowing the genus to survive for millions of years without undergoing important changes. Among the best known species are ''Amphiperatherium bourdellense'', ''A. exile'', ''A. fontense'', ''A. minutum'' and ''A. frequens'', the last surviving species from the Middle Miocene. It was related to the European genus ''

Peratherium ''Peratherium'' is a genus of metatherian mammals in the family Herpetotheriidae that lived in Europe and Africa from the Early Eocene In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It ...

'' and the American genus ''

Herpetotherium ''Herpetotherium'' is an extinct genus of metatherian mammal, belonging to the possibly paraphyletic family Herpetotheriidae. Native to North America from the Eocene to Early Miocene, fossils have been found in California, Oregon, Texas, Florida ...

''.

Palaeoecology

The morphological characteristics of ''Amphiperatherium'' indicates that, unlike similar but smaller genera such as ''Peradectes'', spent most of its time on the ground. Some features of its skeletons, however, such as its prehensile tail, indicates that it was at least a partially arboreal animal, consuming a large variety of foods, including small animals and plants.

Bibliography

*J. J. Hooker. 1996. Mammals from the Early (late Ypresian) to Middle (Lutetian) Eocene Bracklesham Group, southern England. Tertiary Research 16(1-4):141-174 *Furió, M., Ruiz-Sánchez, F.J., Crespo, V.D., Freudenthal, M. & Montoya, P. (published online 2012). The southernmost Miocene occurrence of the last European herpetotheriid Amphiperatherium frequens (Metatheria, Mammalia). Comptes Rendus Palevol. {{Taxonbar, from=Q15041824 Paleogene mammals of Europe Neogene mammals of Europe Prehistoric metatherians Fossil taxa described in 1879 Prehistoric mammal genera