flat-backed millipede vs small tortoiseshell

Polydesmus complanatus compared with Aglais urticae

Key Differences

• flat-backed millipede is Least Concern while small tortoiseshell is Near Threatened.

Taxonomic Classification

Rank	flat-backed millipede	small tortoiseshell
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Arthropoda (Arthropods)	Arthropoda (Arthropods)
Class	Diplopoda (Diplopoda)	Insecta (Insects)
Order	Polydesmida (Polydesmida)	Lepidoptera (Butterflies & Moths)
Family	Polydesmidae	Nymphalidae (Brush-footed Butterflies)
Genus	Polydesmus	Aglais
Species	Polydesmus complanatus	Aglais urticae

Evolutionary Relationship

flat-backed millipede and small tortoiseshell share a common ancestor at the Phylum level: Arthropoda. (Arthropods)

Conservation Status

flat-backed millipede

LC — Least Concern

small tortoiseshell

NT — Near Threatened

Physical Characteristics

Attribute	flat-backed millipede	small tortoiseshell
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

flat-backed millipede

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Denmark, Norway, and Sweden.

small tortoiseshell

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Found across Europe (41 countries). Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

small tortoiseshell

small tortoiseshell (Aglais urticae) is classified as Near Threatened (NT) on the IUCN Red List. Close to qualifying as threatened, with populations that may become vulnerable without conservation action.

Shared Countries

Both species can be found in 3 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden