''Amphiperatherium'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

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 wel ...

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

, closely related to

marsupial Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of marsupials' unique features is their reproductive strategy: the young are born in a r ...

s. It ranged from the Early

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

to the Middle

Miocene The Miocene ( ) is the first epoch (geology), 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 mea ...

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 126 species in 18 genera. Opossums originated in South America and entered North A ...

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 latest 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 Mam ...

'', 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. They are suggested to have b ...

, typical of the Early

Cenozoic The Cenozoic Era ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterized by the dominance of mammals, insects, birds and angiosperms (flowering plants). It is the latest of three g ...

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

and

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

, currently considered either the most primitive of all marsupials, or the sister taxon of

Marsupialia Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of marsupials' unique features is their reproductive strategy: the young are born 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 located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

, but additional fossils were later found in

Spain Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Eur ...

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

Belgium Belgium, officially the Kingdom of Belgium, is a country in Northwestern Europe. Situated in a coastal lowland region known as the Low Countries, it is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeas ...

Czech Republic The Czech Republic, also known as Czechia, and historically known as Bohemia, is a landlocked country in Central Europe. The country is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the south ...

and

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

, 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 to the Early Miocene The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene epoch (ge ...

'' and the American genus '' Herpetotherium''.

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