Paucituberculata is an order of

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

marsupials 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 ...

. Although currently represented only by the seven living species of shrew opossums, this order was formerly much more diverse, with more than 60 extinct species named from the fossil record, particularly from the late Oligocene to early Miocene epochs. The earliest paucituberculatans date to the

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 ...

( Itaboraian

South American land mammal age The South American land mammal ages (SALMA) establish a geologic timescale for prehistoric South American fauna beginning 64.5 Ma during the Paleocene and continuing through to the Late Pleistocene (0.011 Ma). These periods are referred to as age ...

). The group went through a pronounced decline in 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 ...

epoch, which resulted in the extinction of all families of this order except for the living shrew opossums (Caenolestidae). Extinct families of Paucituberculatans include Pichipilidae, Palaeothentidae, and Abderitidae.

Classification

It is one of two clades of

Ameridelphia Ameridelphia is traditionally a superorder that includes all marsupials living in the Americas except for the monito del monte (''Dromiciops''). It is now regarded as a paraphyletic group. Orders The orders within this group are listed below: ...

, a

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 ...

group; genetic studies have shown these animals to be a

sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

Australidelphia Australidelphia is a superorder of marsupials encompassing about three-quarters of all living marsupial species, including all those native to Australasia and one South American species, the monito del monte. Unlike other American marsupials, wh ...

(i.e.,

Didelphimorphia 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 ...

branched off first). However, other studies have shown that shrew opossums branched off first, and thus

is the sister group of Australidelphia. The Paucituberculata were once considered to be closely related to South American polydolopimorph metatherians, however phylogenetic analyses have found this is not true.

Subdivision

The order is subdivided into:Abello, 2007, p.410Paucituberculata
at

Fossilworks Fossilworks was a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world. History Fossilworks was cr ...

.org * †'' Bardalestes'' * †'' Evolestes'' * †'' Fieratherium'' * †'' Riolestes'' * Superfamily Caenolestoidea ** Family Caenolestidae *** ''

Caenolestes The common shrew opossums (genus ''Caenolestes'') are members of the family Caenolestidae. They are found in Colombia, Ecuador, Peru, and Venezuela. The most recently discovered species is ''C. sangay''. Phylogeny See also * List of mammal ...

'' *** †'' Caenolestoides'' *** †'' Gaimanlestes'' *** '' Lestoros'' *** †'' Pliolestes'' *** †'' Pseudhalmarhiphus'' *** '' Rhyncholestes'' *** †'' Stilotherium'' * Superfamily †Palaeothentoidea Palaeothentoidea
at

.org ** †'' Perulestes'' ** †'' Pilchenia'' ** †'' Sasawatsu'' ** Family † Pichipilidae *** †'' Phonocdromus'' *** †'' Pichipilus'' *** †'' Quirogalestes'' ** Family † Abderitidae *** †''

Abderites Abderites or Abderite may refer to: *People associated with the ancient city of Abdera, Thrace *Adherents of the philosophical school of Abdera *Abderite, a reference to Democritus Democritus (, ; , ''Dēmókritos'', meaning "chosen of the ...

'' *** †'' Parabderites'' *** †'' Pitheculites'' ** Family † Palaeothentidae *** †'' Chimeralestes'' *** †'' Hondathentes'' ''Hondathenthes''
at

.org *** Subfamily †Palaeothentinae Paleothentidae
at

.org **** †'' Antawallathentes'' **** †'' Carlothentes'' **** †'' Palaeothentes'' **** †'' Palaepanorthus'' **** †'' Propalaeothentes'' *** Subfamily †Acdestinae **** †'' Acdestis'' **** †'' Acdestoides'' **** †'' Acdestodon'' **** †'' Titanothentes'' **** †'' Trelewthentes''

References

Bibliography

* Shrew opossums Mammal orders Neogene mammals of South America Quaternary mammals of South America Extant Oligocene first appearances Taxa named by Florentino Ameghino Long stubs with short prose {{marsupial-stub