Nephelomys moerex
Encyclopedia
Nephelomys moerex is a species of rodent
in the genus Nephelomys
of family Cricetidae
. The type locality is at Mindo
in western Ecuador
, where it has been recorded together with three other rodents of the oryzomyine
group, Sigmodontomys aphrastus, Mindomys hammondi, and Handleyomys alfaroi, as well as three opossums, Chironectes minimus and unidentified species of Didelphis
and Marmosa
. Mindo is a "tiny agricultural community" located at 0°02'S, 78°48'W and 1264 metres (4,147 ft) above sea level. It was originally described by Oldfield Thomas
as a subspecies
of Oryzomys albigularis. It remained synonymized
under this species until it was recognized as a separate species when the genus Nephelomys
was established for Oryzomys albigularis and related species in 2006.
Unlike in the type species
of the genus, N. albigularis, the lacrimal
bone of the skull is connected primarily to the maxilla
ry bone, not equally to the maxillary and frontal
bones. The incisive foramina
, perforations in the palate
between the incisor
s and the molar
s, are shorter than in some other Nephelomys species, not extending between the molars, and closer to the molars they are wider than further to the front, also unlike in some other species of the genus. These foramina are similar in shape to those in N. nimbosus
. The alisphenoid strut
, an extension of the alisphenoid bone of the skull which separates two openings in the skull, the buccinator–masticatory foramen and the accessory oval foramen, is usually present, although it is more commonly absent in other Nephelomys.
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 Nephelomys
Nephelomys
Nephelomys is a genus of South American oryzomyine rodents found in the Andes from Bolivia to Venezuela, with a westward extension into the mountains of Costa Rica...
of family Cricetidae
Cricetidae
The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, and New World rats and mice...
. The type locality is at Mindo
MINDO
MINDO, or Modified Intermediate Neglect of Differential Overlap is a semi-empirical method for the quantum calculation of molecular electronic structure in computational chemistry. It is based on the Intermediate Neglect of Differential Overlap method of John Pople. It was developed by the group...
in western Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
, where it has been recorded together with three other rodents of the oryzomyine
Oryzomyini
Oryzomyini is a tribe of rodents in the subfamily Sigmodontinae of family Cricetidae. It includes about 120 species in about thirty genera, distributed from the eastern United States to the southernmost parts of South America, including many offshore islands...
group, Sigmodontomys aphrastus, Mindomys hammondi, and Handleyomys alfaroi, as well as three opossums, Chironectes minimus and unidentified species of Didelphis
Didelphis
The six species in the genus Didelphis, commonly known as large American opossums, are members of the Didelphimorphia order....
and Marmosa
Marmosa
The nine species in the genus Marmosa are relatively small Neotropic members of the order Didelphimorphia. This genus is one of four that are known as mouse opossums. The others are Micoureus , Thylamys and Tlacuatzin, the grayish mouse opossum...
. Mindo is a "tiny agricultural community" located at 0°02'S, 78°48'W and 1264 metres (4,147 ft) above sea level. It was originally described by Oldfield Thomas
Oldfield Thomas
Oldfield Thomas FRS was a British zoologist.Thomas worked at the Natural History Museum on mammals, describing about 2,000 new species and sub-species for the first time. He was appointed to the Museum Secretary's office in 1876, transferring to the Zoological Department in 1878...
as a subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
of Oryzomys albigularis. It remained synonymized
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...
under this species until it was recognized as a separate species when the genus Nephelomys
Nephelomys
Nephelomys is a genus of South American oryzomyine rodents found in the Andes from Bolivia to Venezuela, with a westward extension into the mountains of Costa Rica...
was established for Oryzomys albigularis and related species in 2006.
Unlike in the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
of the genus, N. albigularis, the lacrimal
Lacrimal
The term Lacrimal can refer to:*In typography:** A type of Stroke ending *In anatomy** Lacrimal apparatus** Lacrimal artery** Lacrimal bone...
bone of the skull is connected primarily to the maxilla
Maxilla
The maxilla is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible , which is also a fusion of two halves at the mental symphysis. Sometimes The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper...
ry bone, not equally to the maxillary and frontal
Frontal bone
The frontal bone is a bone in the human skull that resembles a cockleshell in form, and consists of two portions:* a vertical portion, the squama frontalis, corresponding with the region of the forehead....
bones. The incisive foramina
Incisive foramen
The fossa incisiva is an opening in the bone of the oral hard palate where blood vessels and nerves may pass. There are four of these openings in the incisive fossa.-Formation:...
, perforations in 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...
between 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 and the molar
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"....
s, are shorter than in some other Nephelomys species, not extending between the molars, and closer to the molars they are wider than further to the front, also unlike in some other species of the genus. These foramina are similar in shape to those in N. nimbosus
Nephelomys nimbosus
Nephelomys nimbosus is a species of rodent in the genus Nephelomys of family Cricetidae. Its type locality is at San Antonio on the northeastern slope of the Tungurahua in the Andes of Ecuador, at an altitude of about . The type series included five individuals.The fur of the upperparts is brown to...
. 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...
, an extension of the alisphenoid bone of the skull which separates two openings in the skull, the buccinator–masticatory foramen and the accessory oval foramen, is usually present, although it is more commonly absent in other Nephelomys.
Literature cited
- Anthony, H.E. 1926. Preliminary report on Ecuadorean mammals. No. 7. American Museum Novitates 240:1–6.
- Ellerman, J.R. 1941. The families and genera of living rodents. Vol. 2. Family Muridae. London: British Museum of Natural History, 690 pp.
- McCain, C.M., Timm, R.M. and Weksler, M. 2007. Redescription of the enigmatic long-tailed rat Sigmodontomys aphrastus (Cricetidae: Sigmodontinae) with comments on taxonomy and natural history. Proceedings of the Biological Society of Washington 120:117–136.
- Musser, G.G. and Carleton, M.D. 2005. Superfamily Muroidea. Pp. 894–1531 in Wilson, D.E. and Reeder, D.M. (eds.). Mammal Species of the World: a taxonomic and geographic reference. 3rd ed. Baltimore: The Johns Hopkins University Press, 2 vols., 2142 pp. ISBN 978-0-8018-8221-0
- Weksler, M., Percequillo, A.R. and Voss, R.S. 2006. Ten new genera of oryzomyine rodents (Cricetidae: Sigmodontinae). American Museum Novitates 3537:1–29.