Amazon River Dolphin vs Common Fat-tailed Mouse Opossum

Inia geoffrensis compared with Thylamys pusillus

Key Differences

• Amazon River Dolphin is Data Deficient while Common Fat-tailed Mouse Opossum is Least Concern.

Taxonomic Classification

Rank	Amazon River Dolphin	Common Fat-tailed Mouse Opossum
Kingdom same	Animalia (hewan)	Animalia (hewan)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class same	Mammalia (mamalia)	Mammalia (mamalia)
Order	Cetacea (Whales & Dolphins)	Didelphimorphia (Didelphimorphia)
Family	Iniidae	Didelphidae
Genus	Inia	Thylamys
Species	Inia geoffrensis	Thylamys pusillus

Evolutionary Relationship

Amazon River Dolphin and Common Fat-tailed Mouse Opossum share a common ancestor at the Class level: Mammalia. (mamalia)

Conservation Status

Amazon River Dolphin

DD — Data Deficient

Common Fat-tailed Mouse Opossum

LC — Least Concern

Physical Characteristics

Attribute	Amazon River Dolphin	Common Fat-tailed Mouse Opossum
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Amazon River Dolphin

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Distributed across Colombia, Ecuador, and Venezuela.

Common Fat-tailed Mouse Opossum

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Amazon River Dolphin

The Amazon River Dolphin (Inia geoffrensis) is a species in the genus Inia. Its conservation status is listed as Data Deficient, indicating insufficient data for assessment. Typically found in diverse terrestrial and aquatic ecosystems.

Common Fat-tailed Mouse Opossum

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.