Coimbra-Filho’s Titi vs Petit opossum-souris

Callicebus coimbrai compared with Thylamys pusillus

Key Differences

• Coimbra-Filho’s Titi is Endangered while Petit opossum-souris is Least Concern.

Taxonomic Classification

Rank	Coimbra-Filho’s Titi	Petit opossum-souris
Kingdom same	Animalia (animal)	Animalia (animal)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class same	Mammalia (mammifères)	Mammalia (mammifères)
Order	Primates (Primates)	Didelphimorphia (Didelphimorphia)
Family	Pitheciidae	Didelphidae
Genus	Callicebus	Thylamys
Species	Callicebus coimbrai	Thylamys pusillus

Evolutionary Relationship

Coimbra-Filho’s Titi and Petit opossum-souris share a common ancestor at the Class level: Mammalia. (mammifères)

Conservation Status

Coimbra-Filho’s Titi

EN — Endangered

Petit opossum-souris

LC — Least Concern

Physical Characteristics

Attribute	Coimbra-Filho’s Titi	Petit opossum-souris
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Coimbra-Filho’s Titi

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Petit opossum-souris

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Coimbra-Filho’s Titi

The Coimbra-Filho's Titi (Callicebus coimbrai), also known as Coimbra-Filho's Titi Monkey, is a small New World monkey in the family Pitheciidae, named in honour of the Brazilian primatologist Adelmar F. Coimbra-Filho. This titi monkey is endemic to the Atlantic Forest of northeastern Brazil, with its range restricted to the states of Sergipe and southern Alagoas—one of the most critically fragmented and threatened biomes on Earth. Adults are small, with reddish-brown fur on the flanks and upperparts, pale grey on the underparts, and an orange-red forehead band. Like all titi monkeys, Callicebus coimbrai is highly social, living in monogamous family groups of 2–5 individuals that engage in elaborate dawn duets and tail-twining behaviour as expressions of pair bonding. The species inhabits Atlantic Forest fragments, including lowland and highland forest patches, riverine gallery forest, and secondary growth, where it subsists on fruits, seeds, leaves, and occasional invertebrates. The Coimbra-Filho's Titi is classified as Endangered by the IUCN due to its severely fragmented range within one of the world's most deforested biomes, with less than 12% of original Atlantic Forest remaining, ongoing habitat loss from agricultural expansion, and small, isolated population sizes highly vulnerable to stochastic extinction events.

Petit opossum-souris

The Common Fat-tailed Mouse Opossum (<em>Thylamys pusillus</em>) is a small marsupial belonging to the genus Thylamys within the family Didelphidae. Like other members of its genus, this species typically stores fat in its tail, which becomes swollen during periods of food abundance and is metabolised during leaner times, a physiological adaptation that provides energy reserves. <em>Thylamys pusillus</em> is generally found in diverse terrestrial and aquatic ecosystems, often in dry woodlands, scrublands, and grassland habitats of South America. The species is assessed as Least Concern on the IUCN Red List, indicating it is not currently considered at risk of extinction. Detailed geographic range data are not available in the current record, but members of this genus are typically distributed across parts of Argentina, Bolivia, Paraguay, and Uruguay. Biological traits including average lifespan, body dimensions, and specific dietary composition remain poorly documented in the scientific literature, though Thylamys species are generally considered omnivorous, often consuming insects, small vertebrates, and plant material.