Herpetotheriidae is an extinct

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

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 well ...

ns, 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 po ...

s. Species of this family are generally reconstructed as

terrestrial Terrestrial refers to things related to land or the planet Earth. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on or near the ground, as opposed to ...

, and are considered morphologically similar to modern

opossums 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 North A ...

. Fossils of herpetotheriids come from North America, Asia, Europe, Africa, and perhaps South America. The oldest representative is '' Maastrichtidelphys'' from the latest

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

(

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval from ...

) of the Netherlands and the youngest member is '' Amphiperatherium'' from the

Middle Miocene The Middle Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene. The sub-epoch lasted from 15.97 ± 0.05 Ma to 11.608 ± 0.005 Ma (million y ...

of Europe. The group has been suggested to be

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

, with an analysis of petrosal anatomy finding that North American ''

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 ...

'' was more closely related to marsupials than the European ''

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 ( ...

'' and ''Amphiperatherium.'' The family includes the following genera: *'' Amphiperatherium'' (

Early Eocene In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by the Eocene Lutetian Age. The Ypresian i ...

, Europe;

synonyms A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

: ''Oxygomphius'', ''Microtarsioides'', ''Ceciliolemur'') *'' Asiadidelphis'' (

Late 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'', "daw ...

Early Oligocene The Rupelian is, in the geologic timescale, the older of two ages or the lower of two stages of the Oligocene Epoch/Series. It spans the time between . It is preceded by the Priabonian Stage (part of the Eocene) and is followed by the Chatti ...

, Kazakhstan and Pakistan) *'' Copedelphys'' (

to Early Oligocene, North America) *'' Entomacodon'' (

Middle 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'', "dawn ...

, North America; synonym: ''Centracodon'') *'' Golerdelphys'' (

Late Paleocene The Thanetian is, in the International Commission on Stratigraphy, ICS Geologic timescale, the latest age (geology), age or uppermost stage (stratigraphy), stratigraphic stage of the Paleocene epoch (geology), Epoch or series (stratigraphy), Serie ...

, North America) *'' Galatiadelphys'' (Middle Eocene, Turkey) *''

'' (Early Eocene to Middle Miocene, North America) *'' Maastrichtidelphys'' (

, Europe) *'' Nortedelphys'' (

Lancian The Lancian was a North American faunal stage of the Late Cretaceous. It was the final stage of the Cretaceous period in North America, lasting from approximately 70.6 to 66 million years ago. Geology Terrestrial sedimentary strata from the Judit ...

, North America) *''

'' (Early Eocene to

Early Miocene The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene Epoch made up of two stages: the Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 Ma to 15.97 ± 0.05 Ma (million years ago). It was prece ...

, Europe;

, Egypt, Oman; synonyms: ''Alacodon'', ''Qatranitherium'') *'' Swaindelphys'' (

Early Paleocene The Danian is the oldest age or lowest stage of the Paleocene Epoch or Series, of the Paleogene Period or System, and of the Cenozoic Era or Erathem. The beginning of the Danian (and the end of the preceding Maastrichtian) is at the Cretaceo ...

, North America) *'' Morotodon'' (Early to Middle Miocene, Uganda) The following genera have been placed in the family, but their placement is disputed or obsolete: *'' Garatherium'' (Early Eocene of Algeria) – possibly an adapisoriculid eutherian *'' Indodelphis'' (Early Eocene of India) – originally referred to Peradectidae *''

Jaegeria ''Jaegeria'' is a genus of flowering plants in the family Asteraceae found from Mexico to South America. The name commemorates Georg Friedrich von Jaeger. ; Species * ''Jaegeria axillaris'' S.F.Blake - Colombia * ''Jaegeria bellidiflora'' (Moc. ...

'' (Early Eocene of India) – a bat *'' Rumiodon'' (

Paleogene The Paleogene ( ; British English, also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period, geologic period and system that spans 43 million years from the end of the Cretaceous Period million yea ...

of Peru) – placement uncertain

References

Literature cited

* * * * * * * * * Prehistoric metatherians Late Cretaceous first appearances Miocene extinctions Prehistoric mammal families {{cretaceous-mammal-stub