Basking shark vs Colombian Oldfield Mouse

Rhincodon typus compared with Thomasomys dispar

Key Differences

• Basking shark is Endangered while Colombian Oldfield Mouse is Data Deficient.

Taxonomic Classification

Rank	Basking shark	Colombian Oldfield Mouse
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Chondrichthyes (Cartilaginous Fish)	Mammalia (Mammals)
Order	Lamniformes (Mackerel Sharks)	Rodentia (Rodents)
Family	Rhincodontidae (Whale Sharks)	Cricetidae
Genus	Rhincodon (Whale Sharks)	Thomasomys
Species	Rhincodon typus	Thomasomys dispar

Evolutionary Relationship

Basking shark and Colombian Oldfield Mouse share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Basking shark

EN — Endangered

Trend: Decreasing ↓

Colombian Oldfield Mouse

DD — Data Deficient

Physical Characteristics

Attribute	Basking shark	Colombian Oldfield Mouse
Diet	Omnivore	—
Average Lifespan	100 years	—
Average Length	12.0 m	—
Average Weight	20.0 t	—

Habitat & Geographic Range

Basking shark

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

Colombian Oldfield Mouse

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Found in Colombia.

Basking shark

The world's largest fish, whale sharks can exceed 12 meters and 20 tonnes, inhabiting tropical and warm temperate oceans worldwide. Despite their massive size, they are harmless filter feeders, consuming plankton, fish eggs, and small fish by swimming open-mouthed through prey-dense water. They undertake vast seasonal migrations following plankton blooms. Endangered due to fishing, boat strikes, and the live fin trade, with population declining by approximately 50% over the past 75 years.

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.