Eliurus petteri
Encyclopedia
Eliurus petteri is a rodent
in the genus Eliurus
found in lowland eastern Madagascar
. First described in 1994, it is most closely related to the smaller Eliurus grandidieri. Virtually nothing is known of its natural history, except that it occurs in rainforest and is nocturnal and solitary. It is threatened by destruction and fragmentation of its habitat and is listed as "Vulnerable
" on the IUCN Red List
.
With a head and body length of 130 to 136 mm (5.1 to 5.4 in), Eliurus petteri is a moderately large species of Eliurus. Its upperparts are gray-brown to gray and contrast sharply with the white underparts. The tail tuft, a characteristic feature of Eliurus, is weakly developed. The skull is delicate and the incisive foramina (openings in the front part of the palate
) are short and short and narrow. The incisor
s are weak.
. Carleton had only three specimens of the new species, which had been collected in 1929, 1956, and 1963 in close proximity in an area of eastern Madagascar. The specific name honors French biologist François Petter, who has contributed to the scientific study of the nesomyines
. In 1998, Carleton and Steven Goodman
described a related species, Eliurus grandidieri, from the Northern Highlands
of Madagascar. Surprisingly, DNA sequence
data suggest that this species is more closely related to Voalavo gymnocaudus than to other species of Eliurus; however, E. petteri has not been studied genetically. Carleton and Goodman reported additional occurrences of E. petteri (though within the same general area) in 2007, and formally recognized the "Eliurus petteri group" (including E. grandidieri and E. petteri) as one of five species groups within the genus.
The common name
s "Petter's Tuft-tailed Rat" and "Petter's Tufted-tailed Rat" have been used for this species. It is now one of twelve species recognized within Eliurus, the most diverse and widespread genus of the native Malagasy rodents (subfamily Nesomyinae
).
Eliurus petteri is a fairly large, long-tailed species of Eliurus that resembles a smaller version of Eliurus webbi. It is larger than the closely related E. grandidieri. The fur is soft and fine. The upperparts appear gray-brown to gray in overall color; individual hairs are light gray for most of their length, then pale buff, and dark brown to black at the tip. Dark guard hair
s—longer hairs projecting above the main fur—are present, but relatively short. The underparts are entirely white, a feature unique for the genus; even E. grandidieri has dark gray underparts. The transition between the coloration of the upper- and underparts is sharp. The mystacial vibrissae (whiskers on the upper lip) are 50 to 60 mm (2 to 2.4 in) long and extend beyond the ears when pressed against the head. In some specimens, the eyes are surrounded by a dark ring. The pinnae (external ears) are dark and appear naked, but are covered by fine brown fur on the outer and by white hairs on the inner surface. The forefeet are entirely white above, but a narrow dark streak is present on the hindfeet. The skin of the tail is dark, sometimes with some white spots on the lower side. Although the tail appears mostly naked, it is covered with inconspicuous hairs. The tail tuft—characteristic of the genus Eliurus—is weakly developed and consists of light brown to grayish brown hairs along the 25 to 30% of the tail closest to the tip.
The skull looks delicate. The interorbital region
(between the eyes) is narrow and hourglass-shaped, and the braincase is smooth; both lack conspicuously developed ridges and shelves. The zygomatic arch
es (cheekbones) are poorly developed. The incisive foramina (openings in the front part of the palate
) are short and narrow. The bony palate ends at the level of the back of the third upper molars
. The alisphenoid strut
(a piece of bone at the back of the skull separating two foramina, or openings) is absent. The strut is present in most Eliurus, but absent in some specimens of E. grandidieri. The subsquamosal fenestra
e (openings in the squamosal bone) are fairly large. The auditory bulla
e are small. The incisor
s are weak and the enamel
on the upper incisors is yellow to light orange. The root of the lower incisor does not project into a distinct capsular process
at the back of the mandible
(lower jaw), a feature shared only with E. grandidieri among species of Eliurus.
), where it occurs from 450 to 1145 m (1480 to 3760 ft) above sea level. It occurs in close proximity with E. minor, E. tanala, and E. webbi, and is probably sympatric with them. Information on the natural history of E. petteri is extremely limited. It occurs in lowland rainforest and is probably arboreal or scansorial (climbing in vegetation). It is nocturnal and solitary and may eat fruits, seeds, and insects. The weak incisors suggest to Carleton that it eats more "indurate" fruits and insects than other Eliurus.
. Furthermore, it may be vulnerable to plague
transmitted by introduced
rodents. Accordingly, it is classified as "Vulnerable
" on the IUCN Red List
.
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
in the genus Eliurus
Eliurus
Eliurus is a genus of rodent in the family Nesomyidae.It contains the following species:* Tsingy Tufted-tailed Rat * Ankarana Special Reserve Tufted-tailed Rat...
found in lowland eastern Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
. First described in 1994, it is most closely related to the smaller Eliurus grandidieri. Virtually nothing is known of its natural history, except that it occurs in rainforest and is nocturnal and solitary. It is threatened by destruction and fragmentation of its habitat and is listed as "Vulnerable
Vulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
" on the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
.
With a head and body length of 130 to 136 mm (5.1 to 5.4 in), Eliurus petteri is a moderately large species of Eliurus. Its upperparts are gray-brown to gray and contrast sharply with the white underparts. The tail tuft, a characteristic feature of Eliurus, is weakly developed. The skull is delicate and the incisive foramina (openings in the front part of the palate
Palate
The palate is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but, in most other tetrapods, the oral and nasal cavities are not truly separate. The palate is divided into two parts, the anterior...
) are short and short and narrow. The incisor
Incisor
Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...
s are weak.
Taxonomy
Eliurus petteri was first described in 1994 by American zoologist Michael Carleton as part of a revision of the genus EliurusEliurus
Eliurus is a genus of rodent in the family Nesomyidae.It contains the following species:* Tsingy Tufted-tailed Rat * Ankarana Special Reserve Tufted-tailed Rat...
. Carleton had only three specimens of the new species, which had been collected in 1929, 1956, and 1963 in close proximity in an area of eastern Madagascar. The specific name honors French biologist François Petter, who has contributed to the scientific study of the nesomyines
Nesomyinae
The Malagasy rats and mice are the sole members of the subfamily Nesomyinae. These animals are the only native rodents of Madagascar, come in many shapes and sizes, and occupy a wide variety of ecological niches. There are nesomyines that resemble gerbils, rats, mice, voles, and even rabbits...
. In 1998, Carleton and Steven Goodman
Steven Goodman
Steven Goodman is an American Conservation Biologist, and field biologist on staff in the Department of Zoology at the Field Museum of Natural History....
described a related species, Eliurus grandidieri, from the Northern Highlands
Northern Highlands
The Northern Highlands are a mountainous biogeographical region of northern Madagascar. The region includes the Tsaratanana Massif and smaller nearby massifs such as Marojejy, Anjanaharibe-Sud, and Manongarivo...
of Madagascar. Surprisingly, DNA sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...
data suggest that this species is more closely related to Voalavo gymnocaudus than to other species of Eliurus; however, E. petteri has not been studied genetically. Carleton and Goodman reported additional occurrences of E. petteri (though within the same general area) in 2007, and formally recognized the "Eliurus petteri group" (including E. grandidieri and E. petteri) as one of five species groups within the genus.
The common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
s "Petter's Tuft-tailed Rat" and "Petter's Tufted-tailed Rat" have been used for this species. It is now one of twelve species recognized within Eliurus, the most diverse and widespread genus of the native Malagasy rodents (subfamily Nesomyinae
Nesomyinae
The Malagasy rats and mice are the sole members of the subfamily Nesomyinae. These animals are the only native rodents of Madagascar, come in many shapes and sizes, and occupy a wide variety of ecological niches. There are nesomyines that resemble gerbils, rats, mice, voles, and even rabbits...
).
Description
| Species | n | Head-body | Tail | Hindfoot | Ear | Mass |
|---|---|---|---|---|---|---|
| E. grandidieri | 42–60 | 111–164 | 144–176 | 26–31 | 19–23 | 44.5–67.5 |
| E. petteri | 2 | 130, 136 | 178, 185 | 30, 31 | 19, 22 | 74.0 (n = 1) |
| n: Number of specimens measured (unless otherwise indicated). All measurements are in millimeters, except body mass in grams. |
||||||
Eliurus petteri is a fairly large, long-tailed species of Eliurus that resembles a smaller version of Eliurus webbi. It is larger than the closely related E. grandidieri. The fur is soft and fine. The upperparts appear gray-brown to gray in overall color; individual hairs are light gray for most of their length, then pale buff, and dark brown to black at the tip. Dark guard hair
Guard hair
Guard hairs are the longest, coarsest hairs in a mammal's coat, forming the topcoat . They taper to a point and protect the undercoat from the elements. They are often water repellent and stick out above the rest of the coat...
s—longer hairs projecting above the main fur—are present, but relatively short. The underparts are entirely white, a feature unique for the genus; even E. grandidieri has dark gray underparts. The transition between the coloration of the upper- and underparts is sharp. The mystacial vibrissae (whiskers on the upper lip) are 50 to 60 mm (2 to 2.4 in) long and extend beyond the ears when pressed against the head. In some specimens, the eyes are surrounded by a dark ring. The pinnae (external ears) are dark and appear naked, but are covered by fine brown fur on the outer and by white hairs on the inner surface. The forefeet are entirely white above, but a narrow dark streak is present on the hindfeet. The skin of the tail is dark, sometimes with some white spots on the lower side. Although the tail appears mostly naked, it is covered with inconspicuous hairs. The tail tuft—characteristic of the genus Eliurus—is weakly developed and consists of light brown to grayish brown hairs along the 25 to 30% of the tail closest to the tip.
The skull looks delicate. The interorbital region
Interorbital region
The interorbital region of the skull is located between the eyes, anterior to the braincase. The form of the interorbital region may exhibit significant variation between taxonomic groups....
(between the eyes) is narrow and hourglass-shaped, and the braincase is smooth; both lack conspicuously developed ridges and shelves. The zygomatic arch
Zygomatic arch
The zygomatic arch or cheek bone is formed by the zygomatic process of temporal bone and the temporal process of the zygomatic bone , the two being united by an oblique suture; the tendon of the Temporalis passes medial to the arch to gain insertion into the coronoid process...
es (cheekbones) are poorly developed. The incisive foramina (openings in the front part of the palate
Palate
The palate is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but, in most other tetrapods, the oral and nasal cavities are not truly separate. The palate is divided into two parts, the anterior...
) are short and narrow. The bony palate ends at the level of the back of the third upper molars
Molar (tooth)
Molars are the rearmost and most complicated kind of tooth in most mammals. In many mammals they grind food; hence the Latin name mola, "millstone"....
. The alisphenoid strut
Alisphenoid strut
In some rodents, the alisphenoid strut is an extension of the alisphenoid bone that separates two foramina in the skull, the masticatory–buccinator foramen and the foramen ovale accessorius...
(a piece of bone at the back of the skull separating two foramina, or openings) is absent. The strut is present in most Eliurus, but absent in some specimens of E. grandidieri. The subsquamosal fenestra
Subsquamosal fenestra
In some rodents, the subsquamosal fenestra is an opening between two parts of the squamosal bone, at the back of the skull. It can be seen in lateral view. Most Oryzomyini have the fenestra, but some species, including those in the genera Nectomys, Sigmodontomys, and Melanomys among others, lack...
e (openings in the squamosal bone) are fairly large. The auditory bulla
Auditory bulla
The auditory bulla is a hollow bony structure on the ventral, posterior portion of the skull of placental mammals that encloses parts of the middle and inner ear. In most species, it is formed by the tympanic part of the temporal bone.In extant primates, the structure is found in tarsiers,...
e are small. The incisor
Incisor
Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...
s are weak and the enamel
Tooth enamel
Tooth enamel, along with dentin, cementum, and dental pulp is one of the four major tissues that make up the tooth in vertebrates. It is the hardest and most highly mineralized substance in the human body. Tooth enamel is also found in the dermal denticles of sharks...
on the upper incisors is yellow to light orange. The root of the lower incisor does not project into a distinct capsular process
Capsular process
In rodents, the capsular process or projection is a bony capsule that contains the root of the lower incisor. It is visible on the labial side of the mandible as a raising in the bone...
at the back of the mandible
Mandible
The mandible pronunciation or inferior maxillary bone forms the lower jaw and holds the lower teeth in place...
(lower jaw), a feature shared only with E. grandidieri among species of Eliurus.
Distribution and ecology
Eliurus petteri is known only from a limited area in the foothills of eastern Madagascar (Toamasina ProvinceToamasina Province
Toamasina is a former province of Madagascar with an area of 71,911 km². It had a population of 2,855,600 . Its capital was Toamasina, the most important seaport of the country....
), where it occurs from 450 to 1145 m (1480 to 3760 ft) above sea level. It occurs in close proximity with E. minor, E. tanala, and E. webbi, and is probably sympatric with them. Information on the natural history of E. petteri is extremely limited. It occurs in lowland rainforest and is probably arboreal or scansorial (climbing in vegetation). It is nocturnal and solitary and may eat fruits, seeds, and insects. The weak incisors suggest to Carleton that it eats more "indurate" fruits and insects than other Eliurus.
Conservation status
Destruction and fragmentation of its habitat are major threats to Eliurus petteri, which is not known to occur in any protected areaProtected area
Protected areas are locations which receive protection because of their recognised natural, ecological and/or cultural values. There are several kinds of protected areas, which vary by level of protection depending on the enabling laws of each country or the regulations of the international...
. Furthermore, it may be vulnerable to plague
Bubonic plague
Plague is a deadly infectious disease that is caused by the enterobacteria Yersinia pestis, named after the French-Swiss bacteriologist Alexandre Yersin. Primarily carried by rodents and spread to humans via fleas, the disease is notorious throughout history, due to the unrivaled scale of death...
transmitted by introduced
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
rodents. Accordingly, it is classified as "Vulnerable
Vulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
" on the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
.