Common Fat-tailed Mouse Opossum vs Common Groundhopper

Thylamys pusillus compared with Tetrix undulata

Taxonomic Classification

Rank	Common Fat-tailed Mouse Opossum	Common Groundhopper
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Chordata (Chordates)	Arthropoda (Arthropods)
Class	Mammalia (Mammals)	Insecta (Insects)
Order	Didelphimorphia (Didelphimorphia)	Orthoptera (Orthoptera)
Family	Didelphidae	Tetrigidae
Genus	Thylamys	Tetrix
Species	Thylamys pusillus	Tetrix undulata

Evolutionary Relationship

Common Fat-tailed Mouse Opossum and Common Groundhopper share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

Common Fat-tailed Mouse Opossum

LC — Least Concern

Common Groundhopper

LC — Least Concern

Physical Characteristics

Attribute	Common Fat-tailed Mouse Opossum	Common Groundhopper
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Fat-tailed Mouse Opossum

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Common Groundhopper

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Luxembourg, Norway, and Sweden.

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.

Common Groundhopper

The common groundhopper, <em>Tetrix undulata</em>, is a small insect belonging to the order Orthoptera, family Tetrigidae. This species has an exceptionally broad ecological tolerance and is typically found across virtually all terrestrial and freshwater habitat types within its range. Its distribution spans Belgium, Denmark, Luxembourg, Norway, and Sweden, reflecting a wide presence across northern and western Europe. Unlike most grasshoppers, groundhoppers typically lack fully developed hind wings in some individuals and are often found on bare ground, mossy substrates, and near water margins. <em>Tetrix undulata</em> is assessed as Least Concern on the IUCN Red List, indicating stable populations across its European range. No dietary information has been provided for this species. Biological traits of this species remain poorly documented in the scientific literature.