Coastal Silver-stiletto vs Complex-toothed Flying Squirrel

Acrosathe annulata compared with Trogopterus xanthipes

Key Differences

• Coastal Silver-stiletto is Least Concern while Complex-toothed Flying Squirrel is Near Threatened.

Taxonomic Classification

Rank	Coastal Silver-stiletto	Complex-toothed Flying Squirrel
Kingdom same	Animalia (animal)	Animalia (animal)
Phylum	Arthropoda (arthropodes)	Chordata (Chordates)
Class	Insecta (insecte)	Mammalia (mammifères)
Order	Diptera (Diptera)	Rodentia (Rodents)
Family	Therevidae	Sciuridae (Squirrels)
Genus	Acrosathe	Trogopterus
Species	Acrosathe annulata	Trogopterus xanthipes

Evolutionary Relationship

Coastal Silver-stiletto and Complex-toothed Flying Squirrel share a common ancestor at the Kingdom level: Animalia. (animal)

Conservation Status

Coastal Silver-stiletto

LC — Least Concern

Complex-toothed Flying Squirrel

NT — Near Threatened

Physical Characteristics

Attribute	Coastal Silver-stiletto	Complex-toothed Flying Squirrel
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Coastal Silver-stiletto

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

Complex-toothed Flying Squirrel

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

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.

Complex-toothed Flying Squirrel

<em>Trogopterus xanthipes</em>, the complex-toothed flying squirrel, is a medium-sized gliding rodent in the family Pteromyidae endemic to China, where it inhabits montane broadleaf and mixed forests at elevations typically between 1,000 and 2,700 metres in provinces including Sichuan, Yunnan, Guizhou, Hubei, and neighbouring regions. This species is the sole member of the genus Trogopterus and is distinguished by complex tooth morphology compared to other flying squirrels. Like all flying squirrels, it possesses a patagium — a gliding membrane stretching between fore and hind limbs — that enables it to glide between trees rather than undertake powered flight. The complex-toothed flying squirrel is nocturnal and arboreal, spending its days sheltering in tree hollows and foraging at night for leaves, bark, seeds, and fungi. Its faeces, known as Wuflingzhi, have been used in traditional Chinese medicine for centuries, leading to trapping pressure in parts of its range. The IUCN classifies this species as Near Threatened, reflecting population decline driven by overhunting for medicinal use and ongoing habitat loss from logging and agricultural encroachment in montane forests. Biological traits including average body mass, lifespan, litter size, and home range are partially documented but detailed population estimates are limited. Conservation measures include legal protections under Chinese wildlife law.