Template:Short description Template:Speciesbox
The long-nosed caenolestid (Rhyncholestes raphanurus), also known as the Chilean shrew opossum or long-nosed shrew opossum, is a shrew opossum that occurs in temperate forests of Argentina and southern Chile. It was first described by American zoologist Wilfred Hudson Osgood in 1924. The long-nosed caenolestid resembles Caenolestes species in morphology. It is characterized by a long, pointed snout, small eyes and ears, and one claw on a digit of each of the thin limbs. Little is known of its behavior; it appears to be terrestrial (lives on land), nocturnal (active mainly at night) and omnivorous. It prefers cool, moist areas, and has a small distribution. It is classified as near threatened by the IUCN.<ref name=iucn/>
Taxonomy and etymologyEdit
The long-nosed caenolestid is the sole member of its genus, and is classified in the family Caenolestidae. It was first described by American zoologist Wilfred Hudson Osgood in 1924. Two subspecies are recognised:<ref name=msw3>Template:MSW3 Paucituberculata</ref><ref name=gardner>Template:Cite book</ref>
- R. r. continentalis Bublitz, 1987: Occurs in Argentina and Chile (type locality: Cerro la Picada in Los Lagos, Chile).
- R. r. raphanurus Osgood, 1924: Occurs in southern Chiloé Island (off the coast of Chile).
A 2013 morphological and mitochondrial DNA-based phylogenetic study showed that the Incan caenolestid (Lestoros inca) and the long-nosed caenolestid form a clade sister to Caenolestes. The cladogram below is based on this study.<ref>Template:Cite journal</ref>
Caenolestid fossils date to as early as the early Eocene (nearly 55 mya). The generic name derives from the Greek words rhynchos ("snout") and lestes ("robber", "pirate"). The specific name comes from the Greek raphanos ("cabbage"), referring to the thick tail of this caenolestid. The Spanish name for this caenolestid, comadrejita trompuda, is the combination of comadreja ("weasel") and trompa ("snout").<ref name="patterson">Template:Cite journal</ref> Other names for this shrew opossum are Chilean shrew opossum or Chilean caenolestid.<ref name=iucn/>
DescriptionEdit
The long-nosed caenolestid resembles Caenolestes species in morphology. In his 1924 account, Osgood recorded external measurements of three specimens. The head-and-body length ranged from Template:Convert, skull length was between Template:Convert and hind feet measured Template:Convert. The smooth coat is dark greyish brown, without countershading (greater pigmentation on the upper side).<ref name=patterson/> It is characterized by a long, pointed snout, small eyes and ears, and one claw on a digit of each of the thin limbs.<ref name=chester>Template:Cite book</ref> This shrew opossum lacks a marsupium<ref>Template:Cite book</ref> (young are attached to the nipples) and has seven nipples, unlike the four typical of other caenolestids.<ref name=gardner/> The tail helps in balancing the body during locomotion; the relatively shorter tail could imply lesser agility in the long-nosed caenolestid in comparison to other caenolestids. Moreover, the tail can be used to store fat,<ref name=patterson/> and is reportedly thickest during early winter.<ref name=gardner/>
A 2007 study recorded dental anomalies such as missing teeth and supernumerary teeth.<ref>Template:Cite journal</ref> The rodent-like incisors help in killing vertebrate prey and searching for insects in crevices.<ref name=patterson/> The pattern of tooth eruption appears to be largely consistent in all caenolestids – the eruption of procumbent (trailing along the surface without spreading out roots) incisors, followed by the development of closely spaced incisors that distance from one another as the mandible grows, and then the eruption of molars and premolars.<ref name=Martin>Template:Cite journal</ref>
Ecology and behaviorEdit
Little is known of the behavior of the long-nosed caenolestid. It appears to be terrestrial (lives on land) and nocturnal (active mainly at night). An omnivore, it feeds on insects and small invertebrates as well as plant material and fungi. The caenolestid appears to live in burrows and fallen logs;<ref name=patterson/> nests may be used temporarily. Lactating females have been reported in May as well as from October to March.<ref name=gardner/> The long-nosed caenolestid is a nocturnal species.<ref name=RhynBosq>Template:Cite journal</ref>
Distribution and statusEdit
The long-nosed caenolestid occurs in temperate forests of Argentina and southern Chile, and up to altitudes of Template:Convert above the sea level (in Osorno Province, Chile). It prefers cool, moist areas.<ref name=gardner/> By 2011 it was known from less than 25 locations, having a very small distribution.<ref>Template:Cite journal</ref> This shrew opossum also marks the southern limit of the distribution of caenolestids.<ref>Template:Cite book</ref> In 2023 the species was reported from 17 sites within the Valdivian Coastal Reserve and the Alerce Costero National Park.<ref name=RhynBosq/> Though locally abundant, the survival of the caenolestid is threatened by deforestation. Its population has declined by nearly 20% since the 1990s due to deforestation and human settlement. The IUCN classifies the long-nosed caenolestid as near threatened.<ref name=iucn/>
ReferencesEdit
External linksEdit
Template:Portal bar Template:Paucituberculata Template:Taxonbar