Common Button Lichen vs Complex-toothed Flying Squirrel

Buellia erubescens compared with Trogopterus xanthipes

Key Differences

• Common Button Lichen is Not Evaluated while Complex-toothed Flying Squirrel is Near Threatened.

Taxonomic Classification

Rank	Common Button Lichen	Complex-toothed Flying Squirrel
Kingdom	Fungi (Fungi)	Animalia (Animals)
Phylum	Ascomycota (Sac Fungi)	Chordata (Chordates)
Class	Lecanoromycetes (Lecanoromycetes)	Mammalia (Mammals)
Order	Caliciales (Caliciales)	Rodentia (Rodents)
Family	Caliciaceae	Sciuridae (Squirrels)
Genus	Buellia	Trogopterus
Species	Buellia erubescens	Trogopterus xanthipes

Conservation Status

Common Button Lichen

NE — Not Evaluated

Complex-toothed Flying Squirrel

NT — Near Threatened

Physical Characteristics

Attribute	Common Button Lichen	Complex-toothed Flying Squirrel
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Button Lichen

Habitat

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

Range

Distributed across Norway, Portugal, Sweden, Taiwan, and United States.

Complex-toothed Flying Squirrel

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Common Button Lichen

<em>Buellia erubescens</em>, commonly known as the common button lichen, is a lichen species with documented occurrences across Asia, Europe, and North America, including countries such as Norway, Portugal, Sweden, Taiwan, and the United States. It typically colonizes diverse terrestrial surfaces, often found on bark, rock, or other substrates in temperate and boreal environments. Common button lichen belongs to the genus <em>Buellia</em> within the family Caliciaceae. As a crustose lichen, it typically forms tightly adhered, crust-like thalli on the surfaces it colonizes, making it characteristic of stable, undisturbed substrates. Biological traits such as average lifespan, thallus size, and biomass of this species remain poorly documented in the scientific literature. The species has not yet been formally evaluated by the IUCN, and its global conservation status therefore remains undetermined. Its occurrence across multiple continents suggests a wide ecological tolerance, though detailed population data and trend assessments are currently lacking for this taxon.

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.