Common Oak Fern vs Common Sun Beetle

Gymnocarpium dryopteris compared with Amara aenea

Key Differences

• Common Oak Fern is Critically Endangered while Common Sun Beetle is Least Concern.

Taxonomic Classification

Rank	Common Oak Fern	Common Sun Beetle
Kingdom	Plantae (Plants)	Animalia (Animals)
Phylum	Tracheophyta	Arthropoda (Arthropods)
Class	Polypodiopsida (Polypodiopsida)	Insecta (Insects)
Order	Polypodiales (Polypodiales)	Coleoptera (Beetles)
Family	Cystopteridaceae	Carabidae
Genus	Gymnocarpium	Amara
Species	Gymnocarpium dryopteris	Amara aenea

Conservation Status

Common Oak Fern

CR — Critically Endangered

Common Sun Beetle

LC — Least Concern

Physical Characteristics

Attribute	Common Oak Fern	Common Sun Beetle
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Oak Fern

Habitat

Found across multiple habitat types including temperate broadleaf and mixed forests, temperate coniferous forests, and boreal forests and taiga, among 4 distinct biome types within the Palearctic biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

Range

Found across Europe (6 countries) and North America (Canada, United States). Currently classified as Critically Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

Common Sun Beetle

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Found across Europe (7 countries) and North America (Canada, United States).

Common Oak Fern

<em>Gymnocarpium dryopteris</em>, the common oak fern, is a delicate terrestrial fern in the family Cystopteridaceae (or Woodsiaceae, depending on classification). Despite its common name, the species is not specifically associated with oak trees; rather, it typically grows in cool, moist, shaded environments including boreal and mixed forests, rocky woodland slopes, stream banks, and shaded cliff faces. <em>Gymnocarpium dryopteris</em> spreads by rhizomes and forms low, spreading colonies with characteristic triangular, three-pinnate fronds that emerge from a slender creeping rootstock. Its geographic range spans Europe and North America, with populations in cool temperate and boreal zones. The species is currently assessed as Critically Endangered in certain regional assessments, suggesting that particular populations face severe decline, likely due to habitat loss, forest fragmentation, and altered hydrology, even if the species retains a broader global range. Biological traits such as lifespan, body size, and diet remain poorly documented at a standardized population level. <em>Gymnocarpium dryopteris</em> is a characteristic indicator of undisturbed cool woodland habitats and is valued for both its ecological role in forest understoreys and its aesthetic appeal.

Common Sun Beetle

<em>Amara aenea</em>, the common sun beetle, is a carabid ground beetle in the family Carabidae, order Coleoptera. It is broadly distributed across Europe and has been introduced to North America, typically inhabiting open, sunny habitats such as arable fields, grasslands, sandy heathlands, and disturbed ground with sparse vegetation. Adults are omnivorous, feeding on seeds, small invertebrates, and plant material, and are considered important predators of weed seeds in agricultural systems. <em>Amara aenea</em> is surface-active during warm, dry conditions, typically exhibiting peak activity in late spring and summer. Like many carabid beetles, it is nocturnal and shelters under stones and debris during the day. Larvae develop in the soil, where they also feed on organic matter and small invertebrates. Biological traits including precise adult lifespan, body length measurements, and detailed prey preferences remain poorly documented at the species level. The species is assessed as Least Concern by the IUCN, reflecting its wide distribution, high adaptability to disturbed environments, and no significant known threats to global population status.

Shared Countries

Both species can be found in 6 countries:

🇧🇪 Belgium 🇨🇦 Canada 🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden 🇺🇸 United States