Bicorbula gallicula

Bicorbula gallicula

(Deshayes, 1857)

Common name Clam
Fossil group Molluscs
Order Myida
Family Corbulidae
Genus Bicorbula
Taxonomic status Accepted
Geological age Ypresian

Summary

Bicorbula gallicula was a small corbulid clam living within soft sediment on the London Clay sea floor. It is interpreted as an infaunal suspension feeder, so the animal remained buried while its siphons brought seawater to the gills for feeding and respiration.

Corbulid clams are compact animals well suited to unstable muddy or sandy seabeds. B. gallicula therefore formed part of the small suspension-feeding community beneath the sediment surface, where burial provided protection while still allowing the animal to exploit food carried in the water above.

Quick Identification

Look for: a small, sturdy corbulid valve with a somewhat elongate triangular outline, unequal valves and fine concentric sculpture; the posterior field is less sharply defined than in many other corbulids.

Diagnostic Features

  • Shell is small, compact and somewhat elongate rather than almost circular.
  • Valves are unequal in size and convexity, as in typical corbulids.
  • Posterior part of the shell forms a modestly narrowed field rather than a strongly produced rostrum.
  • Concentric sculpture is fine and closely spaced rather than coarse.
  • Overall outline and finer sculpture distinguish it from more strongly sculptured or more sharply posteriorly defined corbulids.

Fossil Details

Typical size
About 10–12 mm.
Fossil material
Shell, Internal Mould / Cast
Preservation
Small valves can be overlooked or damaged during extraction. Wear readily softens the fine concentric sculpture, and isolated moulds may lose the valve inequality and hinge details useful for identification.

Similar Species

Recorded Fossil Sites

No fossil-site occurrences have yet been recorded for this species.

References

  • Jeffery, P.; Tracey, S. (1997). The Early Eocene London Clay Formation mollusc fauna of the former Bursledon Brickworks, Lower Swanwick, Hampshire. Tertiary Research, 17(3–4), 75–137 View reference
Last Reviewed
16 August 2026 Reviewed by Sam Harris