Arboreal Thorius vs Coastal Silver-stiletto

Thorius arboreus compared with Acrosathe annulata

Key Differences

• Arboreal Thorius is Critically Endangered while Coastal Silver-stiletto is Least Concern.

Taxonomic Classification

Rank	Arboreal Thorius	Coastal Silver-stiletto
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Chordata (Chordates)	Arthropoda (Arthropods)
Class	Amphibia (Amphibians)	Insecta (Insects)
Order	Caudata (Caudata)	Diptera (Diptera)
Family	Plethodontidae	Therevidae
Genus	Thorius	Acrosathe
Species	Thorius arboreus	Acrosathe annulata

Evolutionary Relationship

Arboreal Thorius and Coastal Silver-stiletto share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

Arboreal Thorius

CR — Critically Endangered

Coastal Silver-stiletto

LC — Least Concern

Physical Characteristics

Attribute	Arboreal Thorius	Coastal Silver-stiletto
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Arboreal Thorius

Habitat

Found across multiple habitat types including tropical and subtropical coniferous forests, tropical and subtropical grasslands and savannas, and Mediterranean forests and woodlands, among 6 distinct biome types spanning the Nearctic and Neotropic realms. Populations are also found in montane and highland environments at higher elevations.

Range

Found in Mexico. Currently classified as Critically Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

Coastal Silver-stiletto

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

Arboreal Thorius

The Arboreal Thorius (Thorius arboreus) is a species in the genus Thorius. It is currently classified as Critically Endangered on the IUCN Red List. Found across multiple habitat types including tropical and subtropical coniferous forests, tropical and subtropical grasslands and savannas, and Mediterranean forests and woodlands, among 6 distinct biome types spanning the Nearctic and Neo.

Coastal Silver-stiletto

Coastal silver stiletto (Acrosathe annulata) is a slender robber fly in the family Therevidae, native to northwestern Europe, including the United Kingdom, France, the Netherlands, Belgium, and Scandinavia. Adults are found on coastal sand dunes and sandy heathland, where they perch on bare sand to ambush small flying insects. Stiletto flies in the family Therevidae are characterised by a slender body, long pointed abdomen, and predatory habits; adults prey on a variety of small dipterans and other flying insects during warm, sunny periods. Larvae develop in sandy soil, where they are also predatory, feeding on other invertebrate larvae. Acrosathe annulata is a habitat specialist restricted to open, sandy coastal habitats with sparse vegetation—environments that have declined substantially across northwestern Europe due to dune stabilisation, recreational disturbance, and the cessation of traditional dune management. The IUCN lists it as Least Concern, though regional conservation bodies in the United Kingdom have flagged population declines. It is considered an indicator of high-quality coastal sand dune habitats and is monitored through national invertebrate surveys.