Colombian Small-eared Shrew vs Common Fat-tailed Mouse Opossum

Cryptotis colombiana compared with Thylamys pusillus

Taxonomic Classification

Rank	Colombian Small-eared Shrew	Common Fat-tailed Mouse Opossum
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class same	Mammalia (Mammals)	Mammalia (Mammals)
Order	Soricomorpha (Soricomorpha)	Didelphimorphia (Didelphimorphia)
Family	Soricidae	Didelphidae
Genus	Cryptotis	Thylamys
Species	Cryptotis colombiana	Thylamys pusillus

Evolutionary Relationship

Colombian Small-eared Shrew and Common Fat-tailed Mouse Opossum share a common ancestor at the Class level: Mammalia. (Mammals)

Conservation Status

Colombian Small-eared Shrew

LC — Least Concern

Common Fat-tailed Mouse Opossum

LC — Least Concern

Physical Characteristics

Attribute	Colombian Small-eared Shrew	Common Fat-tailed Mouse Opossum
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Colombian Small-eared Shrew

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Found in Colombia.

Common Fat-tailed Mouse Opossum

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Colombian Small-eared Shrew

<em>Cryptotis colombiana</em>, the Colombian small-eared shrew, is a diminutive insectivorous mammal belonging to the family Soricidae, endemic to Colombia. This species typically inhabits montane environments, including humid cloud forests and high-altitude grasslands known locally as páramo, where it forages actively through leaf litter and soil for invertebrate prey. Small-eared shrews of the genus <em>Cryptotis</em> are characterised by their notably reduced external ears, high metabolic rates, and nearly constant activity cycles driven by the energetic demands of maintaining body temperature. <em>Cryptotis colombiana</em> is currently assessed as Least Concern by the IUCN, suggesting that its population is relatively stable within its Colombian range. Despite this status, Andean shrews face ongoing pressures from land conversion, cattle grazing in páramo ecosystems, and climate-driven shifts in vegetation zones. The species contributes to soil aeration and invertebrate population regulation within its montane habitat. Biological traits of this species remain poorly documented in the scientific literature.

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.