Brachyura indet.

Brachyura indet.

Higher-taxon identificationIdentified to: Infraorder
Common name Indeterminate Crab
Fossil group Crustaceans
Order Decapoda

Summary

This record is used for true crab remains that can be identified as brachyuran but cannot be assigned to a family, genus or species. Incomplete carapaces and isolated chelae are especially likely to remain at this level.

Quick Identification

Look for: a broad, compact carapace, clearly divided carapace regions and grooves, short side margins, or a heavy claw associated with a crab-like body form. Use this record when the specimen is clearly a true crab but lacks the margins, ornament or regional detail needed for a narrower identification.

Identification Features

  • The carapace is generally broad and compact rather than strongly elongate like a typical lobster.
  • Dorsal carapace surfaces commonly show distinct regional grooves separating major body areas.
  • Front and side margins may preserve lobes, teeth or spines useful for recognising a crab-like carapace.
  • Chelae are robust and may have stout fingers with crushing or cutting teeth.
  • Ventral pieces may include a broad sternum or reduced abdominal plates associated with the compact crab body plan.

Recorded Fossil Sites

Last Reviewed
18 August 2026 Reviewed by Sam Harris