Shrew opossum
309243
225959513
2008-07-16T05:33:08Z
195.158.109.77
{{Taxobox
| name = Shrew opossums
| image = Shrew opossum - Caenolestidae.png
| image_width = 240px
| fossil_range = Late [[Oligocene]] - Recent (for its Order)
| regnum = [[Animal]]ia
| phylum = [[Chordate|Chordata]]
| classis = [[Mammal]]ia
| infraclassis = [[Marsupial]]ia
| ordo = '''Paucituberculata'''
| ordo_authority = [[Florentino Ameghino|Ameghino]], 1894
| familia = '''Caenolestidae'''
| familia_authority = [[Édouard Louis Trouessart|Trouessart]], 1898
| subdivision_ranks = Genera
| subdivision =
''[[Caenolestes]]''<br>
''[[Lestoros]]''<br>
''[[Rhyncholestes]]''
}}
The biological order '''Paucituberculata''' contains the six surviving species of '''shrew opossum''': small, [[shrew]]-like [[marsupial]]s which are confined to the [[Andes]] mountains of [[South America]]. It is thought that the order diverged from the ancestral marsupial line very early. As recently as 20 million years ago, there were at least seven genera in South America. Today, just three genera remain. They live in inaccessible forest and grassland regions of the High Andes. [[Insectivora|Insectivore]]s were entirely absent from South America until the [[Great American Interchange]] three [[annum|Ma]] ago, and are currently present only in the northwestern part of the continent. These shrew opossums fill the same [[ecological niche]], but have lost ground to the [[Eutheria|placental]] invaders. Nevertheless, the ranges of the two groups overlap broadly.
Shrew opossums (also known as rat opossums) are about the size of a small rat (9–14 cm long), with thin limbs, a long, pointed snout and a slender, hairy tail. They are largely carnivorous, being active hunters of [[insect]]s, [[earthworm]]s and small vertebrates. They have small eyes and poor sight, and hunt in the early evening and at night, using their hearing and long, sensitive [[whisker]]s to locate prey. They seem to spend much of their lives in underground burrows and on surface runways.
Largely because of their rugged, inaccessible habitat, they are very poorly known and have traditionally been considered rare. Recent studies suggest that they may be more common than had been thought.
==Classification==
Within the family of the '''Caenolestidae''', six species are known:
* Genus ''[[Caenolestes]]''
** [[Grey-bellied Shrew Opossum]], ''Caenolestes caniventer''
** [[Andean Shrew Opossum]], ''Caenolestes condorensis''
** [[Northern Shrew Opossum]], ''Caenolestes convelatus''
** [[Dusky Shrew Opossum]], ''Caenolestes fuliginosus''
* Genus ''[[Lestoros]]''
** Peruvian or [[Incan Shrew Opossum]], ''Lestoros inca''
* Genus ''[[Rhyncholestes]]''
** [[Long-nosed Shrew Opossum]], ''Rhyncholestes raphanurus''
However, Bublitz suggested in 1987 that there were actually two ''Lestoros'' and ''Rhyncholestes'' species (those listed here plus ''L. gracilis'' and ''R. continentalis''). This is, however, not accepted by most scientists.
==References==
*{{MSW3 Gardner|pages=19-20}}
{{Mammals}}
{{Paucituberculata}}
[[Category:Shrew opossums| ]]
[[category:Living fossils]]
[[cs:Vačíci]]
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[[es:Caenolestidae]]
[[fr:Caenolestidae]]
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[[lt:Žiurkiniai oposumai]]
[[mt:Opossum ġurdiem ta' geddumu twil]]
[[nl:Opossummuizen]]
[[pl:Zbójnikowate]]
[[pt:Paucituberculata]]
[[ru:Ценолестовые]]
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