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 relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the souther ...

marsupials 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 ...

. 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 ICS Geologic timescale, the latest age or uppermost stratigraphic stage of the Paleocene Epoch or Series. It spans the time between . The Thanetian is preceded by the Selandian Age and followed by the Ypresian Age (part ...

(

Itaboraian The Itaboraian ( pt, Itaboraiense) age is a period within the Early Eocene geologic time (53.0–50.0 Ma) epoch of the Paleogene, used more specifically with South American land mammal ages (SALMA). It follows the Riochican and precedes the Cas ...

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 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" ...

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 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 ...

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 the superorder that contains roughly three-quarters of all marsupials, including all those native to Australasia and a single species — the monito del monte — from South America. All other American marsupials are members o ...

(i.e., Didelphimorphia branched off first). The Paucituberculata were once considered to be closely related to South American

polydolopimorph Polydolopimorphia is an extinct order of metatherians, more closely related to extant marsupials than other extinct mammals. Known from the Paleocene-Pliocene of South America and the Eocene of Antarctica, they were a diverse group during the Pal ...

metatherians, however phylogenetic analyses have found this is not true.

Subdivision

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

Fossilworks Fossilworks is 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 cre ...

.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 Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, Repúblic ...

'' *** '' Lestoros'' *** †'' Pseudhalmarhiphus'' *** '' Rhyncholestes'' *** †'' Stilotherium'' * Superfamily † Palaeothentoidea Palaeothentoidea
at

.org ** †'' Perulestes'' ** †'' Pilchenia'' ** †'' Sasawatsu'' ** Family † Pichipilidae *** †'' Pichipilus'' *** †'' Phonocdromus'' *** †'' Pliolestes'' *** †'' Quirogalestes'' ** Family † Palaeothentidae *** †'' Antawallathentes'' *** †'' Carlothentes'' *** †'' Chimeralestes'' *** †'' Hondathentes'' ''Hondathenthes''
at

.org *** Subfamily † Palaeothentinae Paleothentidae
at

.org **** †'' Palaeothentes'' **** †'' Palaepanorthus'' **** †'' Propalaeothentes'' *** Subfamily † Decastinae **** †'' Acdestis'' **** †'' Acdestoides'' **** †'' Acdestodon'' **** †'' Titanothentes'' **** †'' Trelewthentes'' ** Family † Abderitidae *** †'' Abderites'' *** †'' Pitheculites'' *** †'' Parabderites''

References

Bibliography

* Marsupials Mammal orders Marsupials of South America Neogene mammals of South America Quaternary mammals of South America Extant Oligocene first appearances Taxa named by Édouard Louis Trouessart {{marsupial-stub