Common Flat-body vs Medusa Brittlestem

Agonopterix heracliana compared with Psathyrella caput-medusae

Key Differences

Common Flat-body is Least Concern while Medusa Brittlestem is Endangered.

Taxonomic Classification

Rank	Common Flat-body	Medusa Brittlestem
Kingdom	Animalia (Animals)	Fungi (Fungi)
Phylum	Arthropoda (Arthropods)	Basidiomycota (Club Fungi)
Class	Insecta (Insects)	Agaricomycetes (Mushrooms)
Order	Lepidoptera (Butterflies & Moths)	Agaricales (Gilled Mushrooms)
Family	Depressariidae	Psathyrellaceae
Genus	Agonopterix	Psathyrella
Species	Agonopterix heracliana	Psathyrella caput-medusae

Conservation Status

Common Flat-body

LC — Least Concern

Medusa Brittlestem

EN — Endangered

Physical Characteristics

Attribute	Common Flat-body	Medusa Brittlestem
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.

Medusa Brittlestem

Habitat

Typically found in forest floors, decomposing wood, and soil ecosystems.

Range

Distributed across Denmark, Norway, and Sweden. Currently classified as 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.