Common Fieldcap vs Common Rock Borer

Agrocybe pediades compared with Hiatella rugosa

Taxonomic Classification

Rank	Common Fieldcap	Common Rock Borer
Kingdom	Fungi (mantar)	Animalia (hayvan)
Phylum	Basidiomycota (Bazitli mantarlar)	Mollusca (Yumuşakçalar)
Class	Agaricomycetes (Mushrooms)	Bivalvia (Midyeler)
Order	Agaricales (Lamelli mantarlar)	Adapedonta (Adapedonta)
Family	Strophariaceae	Hiatellidae
Genus	Agrocybe	Hiatella
Species	Agrocybe pediades	Hiatella rugosa

Conservation Status

Common Fieldcap

LC — Least Concern

Common Rock Borer

LC — Least Concern

Physical Characteristics

Attribute	Common Fieldcap	Common Rock Borer
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Fieldcap

Habitat

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

Range

Found across Europe (5 countries) and North America (United States).

Common Rock Borer

Habitat

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

Range

Distributed across Denmark, Norway, Sweden, and United States.

Common Fieldcap

The Common Fieldcap (<em>Agrocybe pediades</em>) is a saprotrophic fungus belonging to the genus Agrocybe within the family Strophariaceae. It typically produces small, tan to pale brown cap-shaped fruiting bodies and is often found growing in clusters or scattered on lawns, grassy areas, forest floors, decomposing wood, and soil-rich ecosystems. The species typically inhabits forest floors, decomposing wood, and soil ecosystems, obtaining nutrients by breaking down dead organic matter. Its geographic range includes several European countries — Belgium, Denmark, Norway, Portugal, and Sweden — as well as the United States in North America. <em>Agrocybe pediades</em> is assessed as Least Concern on the IUCN Red List, reflecting its broad distribution and apparent stability. Biological traits of this species, including specific data on fruiting body size, lifespan, and ecological preferences, remain poorly documented in the scientific literature. Like other members of its genus, it typically fruits during warmer months and often appears after rainfall in nutrient-rich grassland and woodland habitats.

Common Rock Borer

<em>Hiatella rugosa</em>, the common rock borer, is a bivalve mollusk in the family Hiatellidae, order Adapedonta. It is distributed across the North Atlantic, with documented records from Denmark, Norway, Sweden, and the United States. The species is assessed as Least Concern on the IUCN Red List, suggesting stable populations across its range. Common rock borers typically inhabit rocky intertidal and subtidal zones, boring into soft substrates including sandstone, shale, chalk, and compacted sediment using mechanical abrasion from their shells. This boring behavior provides the species with protection from predation and wave disturbance. <em>Hiatella rugosa</em> is a suspension feeder, typically extracting phytoplankton and suspended organic particles from the water column through its siphons. The genus Hiatella is considered nearly cosmopolitan, with species occurring from polar to tropical seas. Rock borers are small bivalves, typically reaching only a few centimeters in shell length. They are common components of rocky shore communities and serve as prey for predatory snails, shorebirds, and small fish. Biological traits such as precise lifespan, body measurements, and diet composition remain poorly documented in quantitative ecological studies for this taxon specifically.

Shared Countries

Both species can be found in 4 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden 🇺🇸 United States