Cimar Round Ray vs Colombian Oldfield Mouse

Urotrygon cimar compared with Thomasomys dispar

Key Differences

• Cimar Round Ray is Near Threatened while Colombian Oldfield Mouse is Data Deficient.

Taxonomic Classification

Rank	Cimar Round Ray	Colombian Oldfield Mouse
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Elasmobranchii	Mammalia (Mammals)
Order	Myliobatiformes (Myliobatiformes)	Rodentia (Rodents)
Family	Urotrygonidae	Cricetidae
Genus	Urotrygon	Thomasomys
Species	Urotrygon cimar	Thomasomys dispar

Evolutionary Relationship

Cimar Round Ray and Colombian Oldfield Mouse share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Cimar Round Ray

NT — Near Threatened

Colombian Oldfield Mouse

DD — Data Deficient

Physical Characteristics

Attribute	Cimar Round Ray	Colombian Oldfield Mouse
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Cimar Round Ray

Colombian Oldfield Mouse

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Found in Colombia.

Cimar Round Ray

The Cimar round ray (Urotrygon cimar) is a small stingray in the family Urotrygonidae, found in the eastern Pacific Ocean along the coasts of Central America and northern South America, including the waters of Costa Rica, Panama, Colombia, and Ecuador. It inhabits shallow coastal and estuarine waters over sandy and muddy bottoms, typically at depths of less than 50 meters, where it feeds on small benthic invertebrates and fish. Like other round rays in the genus Urotrygon, it has a nearly circular disc outline, a relatively slender tail, and a venomous caudal spine used defensively against predators. The species is classified as Near Threatened by the IUCN, reflecting its restricted range, vulnerability to coastal habitat degradation, and incidental capture in artisanal and commercial fisheries throughout its range. Bycatch in shrimp trawls and gill nets represents a significant ongoing threat to Urotrygon species throughout the eastern Pacific. Shallow coastal habitats in Central America and Colombia face continued pressure from development, mangrove loss, and pollution. The species' reproductive biology, like that of most Urotrygon rays, involves ovoviviparity, with females giving birth to live young after internal development. Population assessments for this species remain limited, and more data on abundance and mortality rates are needed.

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.