Common Elephant Tusk vs Common Red-legged Robberfly

Antalis entalis compared with Dioctria rufipes

Taxonomic Classification

Rank	Common Elephant Tusk	Common Red-legged Robberfly
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Mollusca (Mollusks)	Arthropoda (Arthropods)
Class	Scaphopoda (Scaphopoda)	Insecta (Insects)
Order	Dentaliida (Dentaliida)	Diptera (Diptera)
Family	Dentaliidae	Asilidae
Genus	Antalis	Dioctria
Species	Antalis entalis	Dioctria rufipes

Evolutionary Relationship

Common Elephant Tusk and Common Red-legged Robberfly share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

Common Elephant Tusk

LC — Least Concern

Common Red-legged Robberfly

LC — Least Concern

Physical Characteristics

Attribute	Common Elephant Tusk	Common Red-legged Robberfly
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Elephant Tusk

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Denmark, Norway, and Sweden.

Common Red-legged Robberfly

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

Common Elephant Tusk

<em>Antalis entalis</em>, the common elephant tusk, is a marine mollusc in the class Scaphopoda, family Dentaliidae, classified as Least Concern by the IUCN Red List. The species is native to European waters and has been documented in Denmark, Norway, and Sweden, inhabiting subtidal and deep benthic zones of the northeastern Atlantic Ocean and North Sea. As a scaphopod, <em>Antalis entalis</em> is characterized by its distinctive curved, tusk-shaped shell that is open at both ends, allowing the animal to partially burrow vertically into sandy or muddy substrates with only the narrow posterior end projecting into the water column. The species feeds on foraminifera and other microscopic organisms in the sediment, capturing prey with specialized tentacle-like structures called captacula that extend through the broader anterior opening of the shell. Scaphopods have limited locomotion and typically remain partially buried throughout their lives. <em>Antalis entalis</em> plays a role in benthic communities as both a consumer of meiofauna and a prey item for predatory fish and invertebrates. Historically, elephant tusk shells of related species were used as currency and ornament by Indigenous peoples of the Pacific Northwest coast. Biological traits of this species remain poorly documented in the scientific literature.

Common Red-legged Robberfly

<em>Dioctria rufipes</em>, the common red-legged robberfly, is a predatory fly in the family Asilidae, order Diptera. It is distributed across northwestern Europe, with confirmed records from Belgium, Denmark, Norway, and Sweden, typically favoring woodland edges, hedgerows, and meadows with abundant vegetation. The species is assessed as Least Concern on the IUCN Red List, reflecting stable populations across its European range. Robberflies in the genus Dioctria are slender, elongated flies characterized by a distinctive long proboscis used to inject paralyzing saliva into prey. <em>Dioctria rufipes</em> typically hunts smaller flying insects, including midges, small flies, and other soft-bodied arthropods, ambushing prey from resting perches on vegetation and capturing it mid-flight. Adults are typically active from late spring to early autumn, coinciding with peak insect activity. The red or reddish-orange coloration of the hind femora is the diagnostic feature that gives this species its common name. Larvae develop in soil or decaying wood, where they are believed to be predatory on other invertebrate larvae. Biological traits such as precise lifespan, body measurements, and diet composition remain poorly documented in quantitative studies. The species is considered an important component of invertebrate predator guilds in European agricultural landscapes.

Shared Countries

Both species can be found in 3 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden