Herpetotheriidae is an extinct

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

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 ...

ns, 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. Species of this family are generally reconstructed as

terrestrial Terrestrial refers to things related to land or the planet Earth, as opposed to extraterrestrial. 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 o ...

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

. They are suggested to have been insectivores. 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 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

(

Maastrichtian The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...

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

Middle Miocene The Middle Miocene is a sub-epoch of the Miocene epoch (geology), epoch made up of two Stage (stratigraphy), stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene. The sub-epoch lasted from 15.97 ± 0. ...

of Europe. The group has been suggested to be

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

, with an analysis of petrosal anatomy finding that North American '' Herpetotherium'' was more closely related to marsupials than the European '' Peratherium'' and ''Amphiperatherium.'' The family includes the following genera: *'' Amphiperatherium'' (

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

, Europe;

synonyms A synonym is a word, morpheme, or phrase that means precisely 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 a ...

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

Late Eocene The Priabonian is, in the International Commission on Stratigraphy, ICS's geologic timescale, the latest age (geology), age or the upper stage (stratigraphy), stage of the Eocene epoch (geology), Epoch or series (stratigraphy), Series. It spans ...

Early Oligocene The Rupelian is, in the geologic timescale, the older of two age (geology), ages or the lower of two stage (stratigraphy), stages of the Oligocene epoch (geology), Epoch/series (stratigraphy), Series. It spans the time between . It is preceded b ...

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

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

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

, 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) *'' Herpetotherium'' (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) *'' Peratherium'' (Early Eocene to

Early Miocene The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages: the Aquitanian age, Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 annum, Ma to ...

, Europe;

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

Early Paleocene The Danian is the oldest age (geology), age or lowest stage (stratigraphy), stage of the Paleocene Epoch or series (stratigraphy), Series, of the Paleogene Period or system (stratigraphy), System, and of the Cenozoic Era or Erathem. The beginnin ...

, North America) *'' Morotodon'' (Early to Middle Miocene, Uganda, placement in the family tentative) 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 Peradectidae is a family of small metatherian mammals, spanning from the Paleocene (or possibly Latest Cretaceous) to the Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma) ...

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

Paleogene The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period Ma (million years ago) to the beginning of the Neogene Period Ma. It is the fir ...

of Peru) – placement uncertain Cladogram after, showing a paraphyletic Herpetotheriidae.

References

Literature cited

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