Bentfin devil ray vs Common Fat-tailed Mouse Opossum

Mobula thurstoni compared with Thylamys pusillus

Key Differences

• Bentfin devil ray is Endangered while Common Fat-tailed Mouse Opossum is Least Concern.

Taxonomic Classification

Rank	Bentfin devil ray	Common Fat-tailed Mouse Opossum
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Elasmobranchii	Mammalia (Mammals)
Order	Myliobatiformes (Myliobatiformes)	Didelphimorphia (Didelphimorphia)
Family	Myliobatidae	Didelphidae
Genus	Mobula	Thylamys
Species	Mobula thurstoni	Thylamys pusillus

Evolutionary Relationship

Bentfin devil ray and Common Fat-tailed Mouse Opossum share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Bentfin devil ray

EN — Endangered

Common Fat-tailed Mouse Opossum

LC — Least Concern

Physical Characteristics

Attribute	Bentfin devil ray	Common Fat-tailed Mouse Opossum
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Bentfin devil ray

Habitat

Found across multiple habitat types including temperate broadleaf and mixed forests, temperate grasslands and steppes, and montane grasslands and shrublands, among 5 distinct biome types within the Neotropic biogeographic realm.

Range

Distributed across Chile and Taiwan. Currently classified as Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

Common Fat-tailed Mouse Opossum

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Bentfin devil ray

The Bentfin devil ray (Mobula thurstoni) is a species in the genus Mobula. It is currently classified as Endangered on the IUCN Red List. Found across multiple habitat types including temperate broadleaf and mixed forests, temperate grasslands and steppes, and montane grasslands and shrublands, among 5 distinct biome types within the Neotropic biogeographic realm.

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.