The northern four-eyed opossum (''Philander vossi'') is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

opossum Opossums () are members of the marsupial order Didelphimorphia () endemic to the Americas. The largest order of marsupials in the Western Hemisphere, it comprises 126 species in 18 genera. Opossums originated in South America and entered North A ...

from

Central America Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...

Taxonomy

This species was originally described by the American mammalogist

Joel Asaph Allen Joel Asaph Allen (July 19, 1838 – August 29, 1921) was an American zoology, zoologist, mammalogy, mammalogist, and ornithology, ornithologist. He became the first president of the American Ornithologists' Union, the first curator of birds and ma ...

in 1901 under the name ''Metachirus fuscogriseus pallidus''; ''fuscogriseus'' is itself a

synonym A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...

of '' Philander melanurus''. It would later be elevated to species by German zoologist

Paul Matschie file: Paul Matschie (BerlLeben 1901-09).JPG, Paul Matschie Paul Matschie (11 August 1861, Brandenburg an der Havel – 7 March 1926, Friedenau) was a German zoologist. He studied mathematics and natural sciences at the Universities of Universi ...

in 1916, before being considered a

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

of '' Philander opossum'' again in 1924 by Gerrit Smith Miller, Jr. It would remain at subspecific status until 2018, when an analysis of the

cytochrome b Cytochrome b is a protein found in the membranes of aerobic cells. In eukaryotic mitochondria (inner membrane) and in aerobic prokaryotes, cytochrome b is a component of respiratory chain complex III () — also known as the bc1 complex or ubiq ...

, nucDNA, and physical characteristics warranted species status again. In 2020 it was found that the name ''pallidus'' was preoccupied by a subspecies of

Derby's woolly opossum Derby's woolly opossum (''Caluromys derbianus''), or the Central American woolly opossum, is an opossum found in deciduous and moist evergreen forests of Central America, from southern Mexico to western Ecuador and Colombia. It was first describ ...

. The subspecies, today ''Caluromys derbianus pallidus'', was originally described as ''Philander laniger pallidus'', and was described two years before ''pallidus'', in 1899. This makes the name ''pallidus'' preoccupied, so in 2020 Alfred L. Gardner and José Ramírez-Pulido decided to make a new species name for this taxa, choosing ''Philander vossi''. ''P. vossi'' is the

sister species 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 ...

to the black four-eyed opossum (''P. nigratus''). This species is recognized by the

American Society of Mammalogists The American Society of Mammalogists (ASM) was founded in 1919. Its primary purpose is to encourage the study of mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence ...

, but not by the

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

, which recognizes neither ''P. pallidus'' nor ''P. vossi''.

Etymology

This species is named after the American mammalogist Robert S. Voss, a prolific mammalogist with an interest in

neotropical The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In biogeogra ...

species such as didelphids and

rodents Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are n ...

. Voss had revalidated this species in 2018 in a paper that also described one of its congeners as a new species and showed the

phylogeny A phylogenetic tree or phylogeny is a graphical representation which shows the evolutionary history between a set of species or Taxon, taxa during a specific time.Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, M ...

of much of this group.

Description

These species are relatively light-furred for a ''Philander'', with gray colors throughout the back, neck, base of the tail, and outer side of the limbs. The head can have some gray colors but tends to be darker, closer to black. The undersides are a yellowish color, extending onto the bottom of the jaw, the cheeks, and in front of the ears. It has two similarly yellowish-creamy-colored spots above each eye. The tail is hairless and black for roughly the basal half its length, and white for the distal half. The feet are pink. When compared to ''P. melanurus'', the closest species genetically and geographically, it tends to be lighter and have more white on the tail. This species ranges from to , with the tail making up to of this length.

Range

This species is currently known only from

Belize Belize is a country on the north-eastern coast of Central America. It is bordered by Mexico to the north, the Caribbean Sea to the east, and Guatemala to the west and south. It also shares a maritime boundary with Honduras to the southeast. P ...

El Salvador El Salvador, officially the Republic of El Salvador, is a country in Central America. It is bordered on the northeast by Honduras, on the northwest by Guatemala, and on the south by the Pacific Ocean. El Salvador's capital and largest city is S ...

, and southern

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

, but is almost certainly also in

Guatemala Guatemala, officially the Republic of Guatemala, is a country in Central America. It is bordered to the north and west by Mexico, to the northeast by Belize, to the east by Honduras, and to the southeast by El Salvador. It is hydrologically b ...

. It may also occur in

Honduras Honduras, officially the Republic of Honduras, is a country in Central America. It is bordered to the west by Guatemala, to the southwest by El Salvador, to the southeast by Nicaragua, to the south by the Pacific Ocean at the Gulf of Fonseca, ...

Nicaragua Nicaragua, officially the Republic of Nicaragua, is the geographically largest Sovereign state, country in Central America, comprising . With a population of 7,142,529 as of 2024, it is the third-most populous country in Central America aft ...

, and

Costa Rica Costa Rica, officially the Republic of Costa Rica, is a country in Central America. It borders Nicaragua to the north, the Caribbean Sea to the northeast, Panama to the southeast, and the Pacific Ocean to the southwest, as well as Maritime bo ...

but more surveying is needed in these regions. As of 2024, no research has been done to find the range border of this species and ''Philander melanurus'', but data from the

citizen science The term citizen science (synonymous to terms like community science, crowd science, crowd-sourced science, civic science, participatory monitoring, or volunteer monitoring) is research conducted with participation from the general public, or am ...

website

iNaturalist iNaturalist is an American 501(c)(3) nonprofit social network of naturalists, citizen scientists, and biologists built on the concept of mapping and sharing observations of biodiversity across the globe. iNaturalist may be accessed via its web ...

indicates it is around the Nicaragua-Costa Rica border. The

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

is from the city of

Orizaba Orizaba (, Otomi: ) is a city and municipality in the Mexican state of Veracruz. It is located 20 km west of its sister city Córdoba, and is adjacent to Río Blanco and Ixtaczoquitlán, on Federal Highways 180 and 190. The city had a ...

in the Mexican state of

Veracruz Veracruz, formally Veracruz de Ignacio de la Llave, officially the Free and Sovereign State of Veracruz de Ignacio de la Llave, is one of the 31 states which, along with Mexico City, comprise the 32 Political divisions of Mexico, Federal Entit ...

. It is the northernmost member of the genus ''Philander''.

References

{{taxonbar, from=Q125492674 Opossums Marsupials of Central America Marsupials of North America Mammals of Mexico Vertebrates of Belize Vertebrates of El Salvador Mammals described in 2020