vs Colombian Oldfield Mouse

Chrysococcus rufescens compared with Thomasomys dispar

Key Differences

• is Not Evaluated while Colombian Oldfield Mouse is Data Deficient.

Taxonomic Classification

Rank		Colombian Oldfield Mouse
Kingdom	Chromista (Chromista)	Animalia (Animals)
Phylum	Ochrophyta (Ochrophyta)	Chordata (Chordates)
Class	Chrysophyceae (Chrysophyceae)	Mammalia (Mammals)
Order	Chromulinales (Chromulinales)	Rodentia (Rodents)
Family	Dinobryaceae	Cricetidae
Genus	Chrysococcus	Thomasomys
Species	Chrysococcus rufescens	Thomasomys dispar

Conservation Status

NE — Not Evaluated

Colombian Oldfield Mouse

DD — Data Deficient

Physical Characteristics

Attribute		Colombian Oldfield Mouse
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Habitat

Native to Europe and South America, inhabiting ecosystems characteristic of the region.

Range

Distributed across Brazil, Denmark, Norway, and Sweden.

Colombian Oldfield Mouse

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Found in Colombia.

Chrysococcus rufescens is a loricate chrysophyte alga in the genus Chrysococcus. The specific epithet rufescens (Latin: reddish or becoming reddish) likely refers to a brownish-golden coloration of the lorica or the pigmented cell contents visible under light microscopy, reflecting the characteristic golden-brown color imparted by fucoxanthin and related carotenoids in chrysophyte chloroplasts. The lorica of C. rufescens encloses the cell and has an apical opening through which the flagellum extends. The species inhabits freshwater environments in northern Europe, including lakes and ponds in Scandinavia. Golden algae (chrysophytes) are typically most abundant in oligotrophic, cold, and poorly buffered waters, making them sensitive indicators of environmental change. C. rufescens contributes to primary production and the microbial food web as a mixotrophic nanoplankton organism capable of both photosynthesis and bacterivory. Chrysophyte loricas are preserved in lake sediments as stomatocysts and scale assemblages, providing long-term paleoecological records. The species has not been evaluated for conservation status by the IUCN and is categorized as Not Evaluated. Accurate identification of C. rufescens requires electron microscopy of lorica ultrastructure.

Colombian Oldfield Mouse

<em>Thomasomys dispar</em>, commonly known as the Colombian Oldfield Mouse, is a small rodent species belonging to the genus <em>Thomasomys</em> within the family Cricetidae. This species is classified as Data Deficient, indicating that insufficient information is currently available to evaluate its conservation status with confidence. It has been documented in Colombia, where it inhabits diverse terrestrial and aquatic-adjacent environments. Members of the genus <em>Thomasomys</em> are typically associated with high-altitude Andean habitats, including páramo grasslands, shrublands, and montane forest edges, where they occupy ground-level microhabitats and burrow in soft soils. These mice are generally omnivorous, consuming seeds, plant material, and invertebrates, though specific dietary data for <em>Thomasomys dispar</em> have not been recorded. Biological traits of this species remain poorly documented in the scientific literature. The Data Deficient classification highlights the need for targeted surveys in Colombian Andean regions to determine population size, distribution, and the ecological requirements of this poorly known rodent.