The Masked Ringtail Possum, Pseudochirulus larvatus, is a marsupial

Marsupial

Marsupials are an infraclass of mammals, characterized by giving birth to relatively undeveloped young. Close to 70% of the 334 extant species occur in Australia, New Guinea, and nearby islands, with the remaining 100 found in the Americas, primarily in South America, but with thirteen in Central...

 possum of the family Pseudocheiridae. It is found in northeastern New Guinea

New Guinea

New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...

 in the Star Mountains

Star Mountains

The Star Mountains are a mountain range in western Papua New Guinea, stretching from the border with Indonesia, at about to the Hindenburg Range...

. the eastern Central Cordillera

New Guinea Highlands

The New Guinea Highlands, also known as the Central Range or Central Cordillera, are a chain of mountain ranges and intermountain river valleys, many of which support thriving agricultural communities, on the large island of New Guinea, which lies to the north of Australia...

, the Huon Peninsula

Huon Peninsula

Huon Peninsula is a large rugged peninsula on the island of New Guinea in Morobe Province, eastern Papua New Guinea. It is named after French explorer Jean-Michel Huon de Kermadec who discovered it along with his personal assistant and porter, Henry Ole. The peninsula is dominated by the steep...

 and the northern coast ranges. Masked Ringtails are arboreal

Arboreal locomotion

Arboreal locomotion is the locomotion of animals in trees. In every habitat in which trees are present, animals have evolved to move in them. Some animals may only scale trees occasionally, while others are exclusively arboreal. These habitats pose numerous mechanical challenges to animals...

 residents of various forest

Forest

A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...

 ecosystems. They are sexually dimorphic

Sexual dimorphism

Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...

 and locally common. This species is sometimes classified as a subpopulation of P. forbesi; however, it has a separate range.