Common Oak Fern vs Epaulard

Gymnocarpium dryopteris compared with Orcinus orca

Key Differences

Common Oak Fern is Critically Endangered while Epaulard is Data Deficient.

Taxonomic Classification

Rank	Common Oak Fern	Epaulard
Kingdom	Plantae (植物)	Animalia (動物)
Phylum	Tracheophyta	Chordata (脊索動物)
Class	Polypodiopsida (ウラボシ綱)	Mammalia (哺乳類)
Order	Polypodiales (ウラボシ目)	Cetacea (Whales & Dolphins)
Family	Cystopteridaceae	Delphinidae (Oceanic Dolphins)
Genus	Gymnocarpium	Orcinus (Orcas)
Species	Gymnocarpium dryopteris	Orcinus orca

Conservation Status

Common Oak Fern

CR — Critically Endangered

Epaulard

DD — Data Deficient

Population: ~50.0K

Trend: Unknown ?

Physical Characteristics

Attribute	Common Oak Fern	Epaulard
Diet	—	Carnivore
Average Lifespan	—	50 years
Average Length	—	8.0 m
Average Weight	—	5.4 t

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.

Epaulard

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and tropical and subtropical grasslands and savannas, among 11 distinct biome types. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Asia (Taiwan), Europe (4 countries), and South America (Colombia, Ecuador, Venezuela).

Common Oak Fern

Gymnocarpium dryopteris, 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. Gymnocarpium dryopteris 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. Gymnocarpium dryopteris is a characteristic indicator of undisturbed cool woodland habitats and is valued for both its ecological role in forest understoreys and its aesthetic appeal.

Epaulard

イルカ科で最大の種であるシャチ（Orcinus orca）は体長最大9メートル、体重6トンに達し、北極から南極まですべての海洋に生息しています。独特の方言、狩猟戦略、集団間で異なる文化的伝統を持つ母系ポッドで生活する頂点捕食者です。一部の集団は魚類を、他の集団は海洋哺乳類を専門に捕食します。天敵はなく、シャチは生息するすべての海洋食物連鎖の頂点に位置します。