Concentric Boulder Lichen vs Epaulard

Porpidia crustulata compared with Orcinus orca

Key Differences

Concentric Boulder Lichen is Vulnerable while Epaulard is Data Deficient.

Taxonomic Classification

Rank	Concentric Boulder Lichen	Epaulard
Kingdom	Fungi (Fungi)	Animalia (Animals)
Phylum	Ascomycota (Sac Fungi)	Chordata (Chordates)
Class	Lecanoromycetes (Lecanoromycetes)	Mammalia (Mammals)
Order	Lecideales (Lecideales)	Cetacea (Whales & Dolphins)
Family	Lecideaceae	Delphinidae (Oceanic Dolphins)
Genus	Porpidia	Orcinus (Orcas)
Species	Porpidia crustulata	Orcinus orca

Conservation Status

Concentric Boulder Lichen

VU — Vulnerable

Epaulard

DD — Data Deficient

Population: ~50.0K

Trend: Unknown ?

Physical Characteristics

Attribute	Concentric Boulder Lichen	Epaulard
Diet	—	Carnivore
Average Lifespan	—	50 years
Average Length	—	8.0 m
Average Weight	—	5.4 t

Habitat & Geographic Range

Concentric Boulder Lichen

Habitat

Native to Europe and North America, inhabiting ecosystems characteristic of the region.

Range

Distributed across Denmark, Norway, Portugal, Sweden, and United States. Currently classified as Vulnerable 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).

Concentric Boulder Lichen

<em>Porpidia crustulata</em>, commonly known as the Concentric Boulder Lichen, is a crustose lichen in the family Porpidiaceae formed through a symbiotic relationship between a fungal partner (mycobiont) and photosynthetic green algae (photobiont). Like all crustose lichens, it grows tightly appressed to its substrate—typically siliceous or acidic rock surfaces including boulders, cliff faces, and pebbles in open, well-lit habitats—forming thin, grayish to pale thalli marked by scattered black apothecia (reproductive discs). <em>Porpidia crustulata</em> derives nutrition entirely through photosynthesis conducted by its algal partner, requiring no external organic food source. The species has been documented in Denmark, Norway, Portugal, Sweden, and the United States, suggesting a broad boreal to temperate distribution across the Northern Hemisphere. It is currently classified as Vulnerable by the IUCN, indicating significant conservation concern, likely linked to threats including air pollution, acidification, quarrying of rocky habitats, and changes in land use that reduce the availability of suitable substrates. Crustose lichens are typically slow-growing, long-lived organisms with limited capacity for rapid range shifts in response to environmental change. Biological traits such as individual lifespan, growth rates, and reproductive output remain poorly documented at the population level.

Epaulard

The largest member of the dolphin family, orcas reach up to 9 meters and 6 tonnes and are found in every ocean from Arctic to Antarctic. Apex predators living in matrilineal pods with distinct dialects, hunting strategies, and cultural traditions that differ between populations. Some populations specialize in fish, others in marine mammals. No natural predators; orcas sit at the top of every marine food chain they inhabit.