Common Drill or Oyster Drill
Phylum: Mollusca, Class: Gastropoda, Order: Neogastropoda, Family: Muricidae, Genus: Urosalpinx, Species: Urosalpinx cinerea · Muricidae (Murex and Rock Snail family) · Gastropod, whole shell, fusiform spiral shape
Species
Urosalpinx cinerea
Shell Type
Gastropod, whole shell, fusiform spiral shape
Family
Muricidae (Murex and Rock Snail family)
Size
Approximately 1 inch (25mm) in length, which is average for this species. Adults typically range from 0.75 to 1.5 inches.
Color & Pattern
Off-white to light gray base color with faint brownish-orange spiral banding and weathered highlights. The colors appear slightly sun-bleached from exposure. The aperture interior is white and smooth.
Rarity
Common, frequently found in intertidal zones and washed ashore along rocky and estuarine beaches.
Habitat
Shallow marine and estuarine waters, typically found in intertidal and subtidal zones down to about 20 feet. Prefers rocky shores, oyster reefs, pilings, and hard substrates where prey is abundant.
Geographic Range
Originally native to the Northwest Atlantic coast of North America from the Gulf of St. Lawrence to Florida, but introduced widely elsewhere, including parts of Europe and the Pacific coast of North America.
Description
A small, sturdy, spindle-shaped gastropod shell featuring a distinct high spire and a moderate anterior canal. The surface is heavily sculptured with prominent rounded axial ribs crossed by fine spiral cords, creating a rough, grid-like texture. The aperture is oval with a simple outer lip and a short siphonal canal.
Key Features
Fusiform profile, prominent axial ribs intersected by spiral cords resulting in a granular texture, a relatively high spired apex, and a small oval aperture with a short, open siphonal canal.
Collector Value
Low to moderate commercial value. While common and inexpensive, they are popular among micro-shell collectors and educational displays focusing on marine ecology and predatory gastropods.
Condition Notes
Good condition with intact structure and original sculptural details preserved. Some minor bleaching and wear typical of beach-worn or shallow-water collected specimens. Collectibility grade: Good.
Interesting Facts
Oyster drills are notorious predators in aquaculture. They bore clean, perfectly circular holes through the shells of oysters, mussels, and clams using a combination of a scraping radula and acidic secretions to access and consume the soft tissue inside.
Ecological Role
As carnivorous predators, oyster drills play a regulatory role in controlling bivalve populations, though they can become destructive pests in commercial oyster fisheries. They serve as prey for crabs, fish, and larger carnivorous gastropods.
Similar Species
Eupleura caudata (Thick-lipped Drill), which has more flattened, wing-like varices, and other small muricids which can be differentiated by exact whorl count and sculpture spacing.
Beach Finding Tips
Search along the wrack line on sandy-rocky beaches, near oyster beds, or examine shell grit and drift material in protected bays and estuaries during low tide.