Bivalvia indet.

Bivalvia indet.

Higher-taxon identificationIdentified to: Class
Common name Indeterminate Bivalve
Fossil group Molluscs

Summary

This record is used for fossil bivalve shells that can be recognised as belonging to a two-valved mollusc but cannot be identified confidently to an order, family, genus or species. Single valves and worn shell fragments often remain at this level.

Quick Identification

Look for: one half of a two-valved shell with a hinge margin, a raised beak or umbo near the hinge, curved growth lines and, where preserved, hinge teeth or internal muscle scars.

Identification Features

  • The shell consists of left and right valves joined along a hinge margin.
  • A raised umbo or beak is commonly positioned close to the hinge.
  • Concentric growth lines usually follow the expanding outline of the valve.
  • Hinge teeth, sockets or a ligament area may be preserved along the dorsal margin.
  • Internal moulds or valve interiors may retain muscle scars, pallial features or the impression of the hinge.

Recorded Fossil Sites

Thanet Formation

Montrose Group
Confirmed
Last Reviewed
18 August 2026 Reviewed by Sam Harris