Caestocorbula regulbiensis

Caestocorbula regulbiensis

(J. Morris, 1854)

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

Summary

Caestocorbula regulbiensis was a small corbulid clam living within soft Palaeogene marine sediment. Like other corbulids, it was probably an infaunal suspension feeder, remaining buried while its feeding currents brought seawater and suspended organic particles to the gills.

Small burrowing clams such as this would have helped process suspended food and transfer it into the seabed food web. Their compact shells also provided protection while the soft-bodied animal lived beneath the sediment surface.

Quick Identification

Look for: a small, compact corbulid clam with unequal valves, a rounded-to-subtrigonal outline and a short posterior end; preserve the hinge and posterior margin wherever possible because worn moulds are not securely species-diagnostic.

Diagnostic Features

  • Shell is small, compact and distinctly inequivalve, with one valve more convex than the other.
  • Overall outline is rounded to subtrigonal rather than elongate.
  • Posterior end is shortened and differentiated from the broader main body of the shell.
  • Exterior is dominated by concentric growth sculpture rather than a regular fan of strong radial ribs.
  • Species-level identification is strongest when valve proportions, posterior region and hinge characters are preserved together.

Fossil Details

Fossil material
Shell, Internal Mould / Cast
Preservation
Small valves are easily chipped at the margins and posterior end. Internal moulds may preserve the general inequivalve form but lose hinge and shell-surface details; strongly worn or incomplete examples should normally remain at genus or family level.

Similar Species

Recorded Fossil Sites

Reculver Sand Member

Thanet Formation
Confirmed
Reculver

Synonyms & Previous Names

Corbula regulbiensis J. Morris, 1854

References

  • MolluscaBase Editorial Board. (2026). MolluscaBase: Caestocorbula regulbiensis (J. Morris, 1854). MolluscaBase View reference
  • Ward, D.J. (1978). The Lower London Tertiary (Palaeocene) succession of Herne Bay, Kent. Report of the Institute of Geological Sciences. Institute of Geological Sciences View reference
Last Reviewed
22 August 2026 Reviewed by Sam Harris