Vetustocytheridea lignitarum

Vetustocytheridea lignitarum

(Dollfus, 1877)

Common name Seed Shrimp
Fossil group Crustaceans
Order Podocopida
Family Cytherideidae
Genus Vetustocytheridea
Taxonomic status Accepted
Geological age Ypresian

Summary

Vetustocytheridea lignitarum is an extinct cytherideid ostracod, a minute benthic crustacean enclosed within a two-valved calcitic carapace. Published Palaeogene occurrences place it in brackish to marginal-marine assemblages and show tolerance of salinity variation, so it can contribute evidence of low-salinity coastal influence but should not be treated as a stand-alone zonal marker.

The animal itself was soft-bodied within the paired valves; the calcitic carapace is the part normally fossilised, either complete or as separated valves.

Quick Identification

Look for: under a stereomicroscope, a small elongate-oval ostracod valve with a deep convex profile, a tapered beak-like anterior end, a rounded posterior margin bearing several stout blunt teeth, and a densely punctate surface. Species-level identification should be made microscopically because abrasion can remove the marginal teeth and soften the punctation.

Diagnostic Features

  • Valve outline elongate-oval in lateral view.
  • Valves strongly convex/deep and slightly unequal.
  • Anterior margin narrows into an attenuated, beak-like end.
  • Posterior margin rounded and bears basally four to six stout, blunt marginal teeth.
  • External surface uniformly punctate with subequal pits, with central pitting tending to be slightly larger.

Fossil Details

Typical size
Published numerical size range not securely established in the sources reviewed.
Fossil material
Ostracod Carapace
Preservation
The calcitic carapace may survive complete, but separated valves are common. Abrasion can blunt or remove the posterior marginal teeth and reduce the apparent punctation; compaction may distort the convex profile. Species-level identification is safest on well-preserved valves examined microscopically.

Recorded Fossil Sites

Synonyms & Previous Names

Cytheridea lignitarum Dollfus, 1877

References

  • Dollfus, G. (1876). Description et classification des dépôts tertiaires des environs de Dieppe. Annales de la Société Géologique du Nord, 4, 19–33 View reference
  • Lord, A. R., Whittaker, J. E. & King, C. (2009). Paleogene. In Whittaker, J. E. & Hart, M. B. (eds), Ostracods in British Stratigraphy, 373–409. The Geological Society, London. View reference
Last Reviewed
22 August 2026 Reviewed by Sam Harris