Common Flat-body vs Common Frillwort

Agonopterix heracliana compared with Fossombronia pusilla

Key Differences

• Common Flat-body is Least Concern while Common Frillwort is Critically Endangered.

Taxonomic Classification

Rank	Common Flat-body	Common Frillwort
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Arthropoda (Arthropods)	Marchantiophyta (liverwort)
Class	Insecta (Insects)	Jungermanniopsida (Jungermanniopsida)
Order	Lepidoptera (Butterflies & Moths)	Fossombroniales (Fossombroniales)
Family	Depressariidae	Fossombroniaceae
Genus	Agonopterix	Fossombronia
Species	Agonopterix heracliana	Fossombronia pusilla

Conservation Status

Common Flat-body

LC — Least Concern

Common Frillwort

CR — Critically Endangered

Physical Characteristics

Attribute	Common Flat-body	Common Frillwort
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Flat-body

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

Common Frillwort

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, temperate broadleaf and mixed forests, and Mediterranean forests and woodlands spanning the Indomalayan and Palearctic realms. Populations are also found in montane and highland environments at higher elevations.

Range

Found across Asia (Taiwan) and Europe (5 countries). Currently classified as Critically Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

Common Flat-body

<em>Agonopterix heracliana</em> is a moth belonging to the family Depressariidae within the order Lepidoptera. Commonly known as the common flat-body, this species is named for the flattened resting posture characteristic of the genus Agonopterix. The species is classified as Least Concern on the IUCN Red List, with no indication of significant population decline. <em>Agonopterix heracliana</em> is distributed across northwestern Europe, with documented occurrences in Belgium, Denmark, Norway, and Sweden. Larvae of this species are typically associated with plants in the family Apiaceae, particularly hogweed (Heracleum sphondylium) and related umbellifers, upon which they feed while sheltering in rolled or folded leaves. Adults are typically brownish with subtle markings and are active from late summer through winter and early spring, overwintering as adults — an unusual life history trait among moths. The species inhabits hedgerows, woodland margins, and meadows where its host plants are abundant. Biological traits of this species remain poorly documented in the scientific literature.

Common Frillwort

<em>Fossombronia pusilla</em>, commonly known as the common frillwort, is a small liverwort belonging to the family Fossombroniaceae within the division Marchantiophyta. This non-vascular bryophyte typically grows in moist, disturbed soils, clay banks, and damp pathways across its range in Europe and parts of Asia. The thallus is typically lobed and frilly in appearance, giving the species its common name. <em>Fossombronia pusilla</em> favors habitats with high moisture and reduced competition, often colonizing bare or sparsely vegetated ground following disturbance. Its geographic range spans temperate regions of western and central Europe into Asia, though populations have become increasingly fragmented. The species is currently assessed as Critically Endangered on the IUCN Red List, reflecting severe population declines likely driven by habitat loss, land drainage, and agricultural intensification. Biological traits such as lifespan, body size, and diet remain poorly documented for this species, as is common among many small bryophyte taxa. Like other liverworts, <em>Fossombronia pusilla</em> reproduces both sexually through spores and vegetatively. Conservation of this species depends on protecting moist, low-competition microhabitats and reducing disturbance to its specialized substrates.

Shared Countries

Both species can be found in 3 countries:

🇧🇪 Belgium 🇳🇴 Norway 🇸🇪 Sweden